Heterocyclic Chemistry Volume 1 pot

Heterocyclic Chemistry
Volume
1
A
Specialist Periodical Report
~~
Heterocyclic Chemistry
Volume 1
A
Review
of
the Literature Abstracted
between
July
1978
and
June 1979
Senior Reporters
H.
Suschitzky
and
0.
Meth-Cohn
Department
of
Chemistry and
Applied Chemistry, University of Salford
Reporters

G.
V.
Boyd
Chelsea College, London
G.
M.
Brooke
University of Durham
G.
P.
Ellis
UWIST, Cardiff
S.
Gronowitz
University of Lund, Sweden
D.
Le
Count
ICI
Pharmaceuticals, Macclesfield, Cheshire
P.
A.
Lowe
University of Salford
T.
J.
Mason
Lanchester Polytechnic, Coventry
J.
M.

Mellor
University of Southampton
F.
G.
Riddell
University
of
Stirling
R.
K.
Smalley
University of Salford
R.
C.
Storr
University
of
Fiverpool
The Royal Society
of
Chemistry
Burlington House, London
WIV
OBN
British
Library Cataloguing in Publication Data
Heterocyclic chemistry
(Royal Society
of
Chemistry. Specialist periodical reports).

VOl.
1
1.
Heterocyclic compounds
I. Suschitzky, Hans
11.
Meth-Cohn, Otto 111. Series
547'.59 QD400
ISBN 0-85 186-970-X
ISSN 0144-8773
RSC Members copy
ISBN 0-85404-970-3
Copyright
@
1980
The Royal Society
of
Chemistry
All
Rights Reserved
No
part
of
this
book
may be reproduced or transmitted
in
any form
or by any means
-

graphic, electronic, including photocopying, recording,
taping, or information storage and retrieval systems
-
without
written permission from The Royal Society of Chemistry
Set
in
Times on Linotron and printed offset
by
J.
W.
Arrowsmith
Ltd., Bristol, England
Made
in
Great Britain
In
trod
uc
tion
Heterocyclic Chemistry represents a vast and important area of research which is
of interest to a wide spectrum
of
chemists. This is amply documented by the fact
that various journals, societies, and interest groups have sprung up entirely
devoted to the pursuit of heterocyclic chemistry. Surprisingly though, there exists
to our knowledge
no
single
periodical review alerting the reader on an annual

basis to important developments of the subject. We have now been able to
persuade the Royal Society of Chemistry to allow
us to remedy this omission with
the help of eleven specialists. This new series of Specialist Periodical Reports,
apart from making economic sense, will facilitate the finding of information on
heterocyclic topics since it combines the material previously reviewed in a
piecemeal way in three different series of volumes. These were ‘Saturated
Heterocyclic Chemistry’, ‘Aromatic and Heteroaromatic Chemistry’ (both of
which are now discontinued),
and the still thriving volume on ‘Organic
Compounds of Sulphur, Selenium, and Tellurium’, which has surrendered its
heterocyclic parts but will continue to report
on
P-lactam antibiotic chemistry.
The literature coverage is essentially based
on
volumes
89
and
90
(i.e.
July
1978
to June
1979)
of
Chemical Abstracts,
but, in order to provide continuity between
this new series and previous (now deleted) reports, the period covered in certain
chapters was extended accordingly. Our authors have endeavoured to include all

significant contributions in a selective and concise rather than an encyclopaedic
manner.
We have retained the newly introduced format of Volume
7
of the series
‘Aromatic and Heteroaromatic Chemistry’,
i.e.
proceeding from small to large
rings and giving preference to the smaller heterocycle in fused systems. Excep-
tionally, if the smaller ring is trivial to the chemistry
of
the annelated system, the
larger ring is given priority. In cases of uncertainty, both ring-chapters will carry
the information, as we felt this to be a justified overlap. Articles
on ‘Bridged
Systems’ and ‘Conformation’ have been added because of their relevance to the
chemistry of saturated heterocycles. Review references are mostly quoted at the
beginning of each chapter, and the contents list has been drawn up with the aim of
serving as a broad index for easy location of points of interest.
In
future issues it is
hoped to follow similar schemes in each chapter as far as possible. We intend to
include reviews on specific topics of current interest from time to time.
Our authors provided
us
with the manuscripts in good time and we thank them
and the editorial staff
of
the Royal Society of Chemistry for their efficiency, which
made our own task a pleasure.

vi
Introduction
The Senior Reporters, as always, would welcome comments, criticism, and
suggestions concerning this new venture.
H.
SUSCHITZKY
&
0.
METH-COHN
Postscript: Owing
to
a printers’ dispute, the publishing date
of
this volume
was
considerably delayed. This is much regretted. Volumes in this series are normally
scheduled
to
appear in the early Summer.
H.S.
&
0.M C.
Contents
Chapter
1
Three-membered
Ring
Systems
By
T.

J.
Mason
1
Oxirans
Preparation
Catalytic Oxidation
of
Alkenes, using Oxygen
or
Oxygen-containing Gases
Oxidation
of
Alkenes by Peroxy-acids
Catalytic Oxidation
of
Alkenes, using Peroxides
Halohydrin Cyclizations and Related Reactions
Syntheses Related to the Darzens Reaction
Synthesis
of
Chiral Oxirans
Synthesis
of
Fused Aromatic Oxides
Miscellaneous Syntheses
Spectra and Theoretical Chemistry
Reactions
Electrophilic Ring-opening
Kinetic studies
Cyclization reactions

Miscellaneous reactions
Nucleophilic Ring-opening
With oxygen and nitrogen nucleophiles
With carbanions
Reduction and Elimination
Thermal and Photochemical
With Organometallic Compounds
Miscellaneous
2
Oxirens
3
Aziridines
Preparation
Direct Insertion
Cyclizations
via
Ring Contraction
Spectroscopic and Theoretical Studies
Reactions
Retention
of
the Aziridine Ring
Ring-opening to Acyclic Compounds
Formation
of
other Ring Systems
4
Azirines
Preparation
~

1
1
1
1
3
4
6
7
8
10
11
12
13
14
14
14
16
17
17
18
19
21
22
24
25
26
26
26
27
28

29
30
30
31
32
34
34

Vlll
Heterocyclic Chemistry
Reactions
35
Photochemical and Thermal
35
Cyclization
to
Five- and Six-membered Heterocyclic
Systems
With Metal Carbonyls
5
Thiirans
Preparation
Reactions
Chemistry
of
Thiiranium
Ions
6
Thiirens
7

Diaziridines
8
Diazirines
9
Oxaziridines
10
Thiazirines
Chapter
2
Four-membered
Ring
Systems
By
R.
C.
Storr
1
Reviews
2
Systems containing One Nitrogen Atom
Azetidines and Azetines
Azetidinones
3
Systems containing Two Nitrogen Atoms
4
Systems containing One Oxygen Atom
Oxetans
2-Oxetanones (p-Lactones)
Dioxetans
5

Systems containing Two Oxygen Atoms
6
Systems containing Sulphur
7
Miscellaneous
Chapter
3
Five-membered
Ring
Systems
By
G.
V.
Boyd,
P.
A.
Lowe,
and
S.
Gronowitz
36
37
38
38
39
39
40
41
42
42

44
45
45
45
45
47
53
56
56
58
59
59
63
66
67
Part
I
Thiophens and their Selenium and Tellurium Analogues
67
By
S.
Grono
wit2
1
General
67
2
Monocyclic Thiophens
Synthesis by Ring-closure Reactions
68

68
Con tents
ix
Physical Properties
Electrophilic Substitution
Electrophilic Ring-closure Reactions
Nucleophilic Substitution
Organometallic Derivatives
Cycloadditions and Photochemistry
The Structure and Reactions
of
Hydroxy-, Mercapto-,
and Amino-thiophens
Side-chain Reactivities
Carbene and Nitrene Reactions
‘Benzylic’ Reactivity
Reactions of Thiophen Aldehydes and Ketones
Reactions of Carboxy- and Cyano-thiophens
Various Side-chain Reactions
Reaction at Sulphur: Thiophen Dioxides
Di- and Tetra- hydrothiop hens
Bi- and Poly-heterocycles
Naturally Occurring Thiophens
Thiophen Analogues of Steroids
Thiophens of Pharmacological Interest
3
Benzothiophens and their Benzo-fused Systems
Synthesis
of
Benzothiophens

Physical Properties
Substitution Reactions
Side-chain Reactions
Benzo[b]thiophen S-Oxides
Benzo[c]thiophens
Dibenzothiop hens
Pharmacologically Active Compounds
4
Thiophen Analogues of Polycyclic Aromatic
Hydrocarbons
Analogues of Phenanthrene
Analogues of Phenalenes and Phenalenium Ions
Thiophen-fused Tropylium Ions and Related Compounds
5
Thiophens Fused to Five-membered Heteroaromatic Rings
Thiophen- and Pyrrole-fused Thiophcns,
Pyrazole-, Thiazole-, and Isothiazole-fused Thiophens
and Related Compounds
and Related Systems
6
Thiophens Fused
to
Six-membered Aromatic
Heterocyclic Rings
Thiophen Analogues
of
Quinoline
Thiophen Analogues of Isoquinoline
73
74

75
76
77
78
79
81
82
84
85
86
87
87
88
90
93
93
95
97
97
97
97
99
100
100
100
101
101
101
102
103

103
103
104
105
105
105
X
Heterocyclic Chemistry
Pyrimidine-fused Systems
Pyrazine- and Triazine-fused Systems
Miscellaneous Fused Systems
7
Selenophens and Tellurophens
Monocyclic Selenophens
Benzoselenophens and their Benzo-fused Derivatives
Selenophens Fused to Five-membered Aromatic Rings
Selenophens Fused to Six-membered Aromatic Rings
Tellurophens
Tel
I
u
r
i u
m
ByP.
A.
Lowe
Part
II
Systems containing Nitrogen and Sulphur, Selenium, or

1
Introduction and Reviews
2 Isothiazoles
Synthesis
From Oxathiazolones (Type B)
From Meso-ionic
1,3,2-0xathiazolium-5-olates
(Type B)
From
P-
Amino-cinnamates (Type C)
From Enamines and Isothiocyanates (Type
C)
From
Benzothiazolyldithioazetidinone
(Type C)
From Thione-S-imides (Type
D)
From Enamines and Perchloromethanethiol (Type E)
From
y-
Hydroxy-alkenesulphonamides
(Type F)
Physical Properties
Chemical Properties
Alk ylation
Nucleophilic Reactions
Cycloaddition
3
1,2-Benzisothiazoles, their 1-Oxides, and their

1,l-Dioxides
Synthesis
Reactions
4
1,2-Benzisoselenazole and 1,2-Benzisotellurazole
5
2,l-Benzisothiazoles
6
Other Condensed Ring Systems incorporating Isothiazole
Thieno[3,4-c]isothiazoles
Furano-, Thieno-, Pyrrolo-, and Pyrazolo-
[4,5
-d]isot hiazoles
Thiazolo[4,5 -c]isothiazole
Isothiazolo[4,5-b]pyrazines
C
yclohep
t
a[
c
]is0
t
hiazole
P yrido[
3’,
2’
:
4,5] thieno[
3,2
-

c
]is0 t hiazole
Isothiazolo[4,3-c]quinolines
106
107
107
107
107
108
108
109
109
109
109
110
110
110
111
111
111
112
112
112
112
113
113
113
113
113
114

114
115
116
116
117
117
117
117
117
117
118
118
Con tents
xi
Isothiazolo[5,4-b]quinoline
Naphtho[ 1,2-d]isothiazoIe
Nap
h
t ho[ 2,l -d]iso thiazole
Miscellaneous
7
Thiazoles
Synthesis
Hantzsch's Synthesis (Type
A;
S-C-N
+
C-C)
Type C Syntheses (C-C-N-C
+

S)
Type
F
Syntheses (C-N-C-S
+
C)
Type
G
Syntheses (N-C-S-C-C)
Type
J
Syntheses (C-S-C-N-C)
Type
K
Syntheses (C-C-N-C-S)
Synthesis
of
Meso-ionic Thiazoles
Miscellaneous
Physical Properties
Chemical Properties
Electrophilic Reactions
Nucleophilic Reactions
Homolytic Reactions
Photochemistry
Reactions
of
2-Amino-thiazoles
Reactions
of

Thiazolium Salts
Reactions
of
Meso-ionic Thiazoles
Miscellaneous
8
A'-Thiazolines
Synthesis
Type
B
Syntheses (C-C-N
+
C-S)
Type
E
Syntheses (N-C-C-S
+
C)
Type
K
Syntheses (C-C-N-C-S)
Physical Properties
Chemical Properties
9
A3-Thiazolines
10
A4-Thiazolines
Synthesis
Reactions
11

Thiazolidines
Synthesis
Type A Syntheses (S-C-N
+
C-C)
Type
B
Syntheses (C-C-N
+
C-S)
Type C Syntheses (C-C-N-C
+
S)
Type
D
Syntheses (C-C-S
+
C-N)
Type
E
Syntheses (N-C-C-S
+
C)
Type
G
Syntheses (C-C-S-C-N)
Physical Properties
118
118
118

119
119
119
119
120
120
121
121
121
121
122
122
123
123
123
123
123
124
125
125
125
125
125
125
126
126
126
126
127
127

127
127
128
128
128
128
128
128
129
129
129
xii
Chemical Properties
Rhodanines, Isorhodanines, and Thiorhodanines
12
Selenazoles
13
Benzothiazoles
Synthesis
From ortho- Amino-benzenethiols (Type A;
Type
B
Syntheses (C6Hs-N-C-S)
Type C Syntheses (NhC6H4-S-C)
Type
G
Syntheses (C6H5-s-c-N)
Type C6Hs-N-c
+
S

Syntheses
S-C6H4-N
+
C)
Physical Properties
Chemical Properties
Substitution Reactions
Addition Reactions
Alkylation
Reactions
of
Thiazolium Salts
Ring-cleavage Reactions
14
Condensed Ring Systems incorporating Thiazole
Structures comprising Two Five-membered Rings
(53)
Thiazolo[2,3-e]tetrazoles
[CN4-C3NS]
Thiazolo-[2,3-c]- and
-[3,2-b]-[1,2,4]triazoles
Thiazolo[3,4,-c]oxazole [C3NO-C3NS]
Thiazolo[4,5-d]thiazoles
[C3NS-C3NS]
Pyrazolo[3,4-d]thiazole [C3NS-C3N2]
Imidazo[2,1 -b]thiazoles [C3NS-C3Nz]
Pyrrolo[2,1-b]thiazoles [C,NS-C4N]
Furano[2,3-d]thiazoles [C3NS-C40]
Cyclopentenothiazol-6-one
[C3NS-C,]

[C~NJ-CWI
Structures comprising One Five-membered and One
Six-membered Ring (5,6)
Thiazolo[3,2-a]- 1,3,5-triazines [C3NS-C3N3]
Thiazolo[4,5 -d]pyridazines [C3NS-C4Nz]
Thiazolo[3,2-~]pyrimidines
[C3NS-C4N2]
Thiazolo-[4,5 -d]
-
and
-[
5,441 -pyrimidines [C3NS-C4N2]
Thiazolo[3,4-a]pyrazines
[C3NS-C4N,]
Thiazolo[4,5-b]pyrazines
[C3NS-C4N2]
Thiazolo[ 3,2
-a
Ipyridines
[
C3NS-C5N]
Thiazolo[3,4-a]pyridines
[C3NS-CSN]
Thiazolo[5,4-b]pyridines
[C3NS-CSN]
Pyrano[4,3-d]thiazoles [C3NS-C50]
Structures comprising One Five-membered Ring and One
Seven-membered Ring
(5,7)
Thiazolor4.5-claze~ines TC,NS-C,Nl

Heterocyclic Chemistry
~
LI
2
1
La
">
145
130
131
132
133
133
133
134
134
134
135
135
136
136
137
138
138
139
139
139
139
139
140

140
140
140
141
141
142
142
142
142
142
143
143
143
143
145
145
145
145
Contents

Xlll
Structures comprising Two Five-membered Rings and One
1,2,4 -Triazolo[3,4
-
blbenzothiazole [C3N3-C3NS-C6]
Thiazolo[2,3-b]benzothiazoles
[C3NS-C3NS-C6]
Thiazolo[4,5-d]indazole [C3NS-C3N2-C6]
Benzo[ 1,2-d
;

3,4-d’]-bis- thiazoles
[
C3NS-C3NS-C6]
Thiazolo[3,2-a]benzimidazoles
[C3NS-C3N2-C6]
Thiazolo[5,4-c]benzimidazoles
[C3NS-C3N2-C6]
Imidazo[2,1 -b]benzothiazoles [C3NS-C3N2-C6]
Thiazolo[3,4-a]indoles [C3NS-C4N-C6]
Thia~olo[5,4-
b
lindoles [C3NS-C4N-C6]
Pyrrolo[2,1 -b]benzothiazoles [C3NS-C4N-C6]
Benzo[ b]furano[ 2,3 -d]thiazole [c3Ns-C40-c6]
Six-membered Ring
(5,5,6)
Structures comprising One Five-membered Ring and Two
1,3,5 -Triazino[2,1 -b]benzothiazole [C3NS-C3N3-C6]
8-Thia-l,4-diazacyc1[3.3.2]azines
[C3NS-C4N2-C4N2]
Pyrano[4,3-d]thiazolo[3,2-a]pyrimidines
Pyrimido[2,1
-b
]benzothiazoles
[
c3Ns-c4N2-c6]
Thiazolo-[ 2,3-b]-,
-
[3,2
-a

I-, and -[3,2-c]-quinazolines
Thiazolo[4,5
-
b]&inoxalines
[
C3NS-C4N2-C6]
Thiazolo-[3,2-a]-, -[4,5-g]-, -[5,4-g]-, -[4,5-h]-, and
-[5,4-h]-quinolines [c3Ns-c5N-c6]
Thiazolo-[2,3-a]- and -[3,4-b]- isoquinolines
Naphtho-[1,2-d]- and -[2,1-d]-thiazoles [C3NS-C6-C6]
Six-membered Rings (5,6,6)
[C3NS-C4N2-C50]
[C,NS-C,N -C6]
[
C3NS-CSN-CJ
Other Condensed Systems incorporating Thiazole
15
Thiadiazoles and Selenadiazoles
1,2,3-Thiadiazoles
Synthesis
Physical Properties
Chemical Properties
1,2,3 -Selenadiazoles
1,2,4-Thiadiazoles
Synthesis
Physical Properties
Chemical Properties
1,2,4-Selenadiazoles
1,3,4-Thiadiazoles
Synthesis

Physical Properties
Chemical Properties
Condensed 1,3,4-Thiadiazoles
1,3,4-Selenadiazoles
145
145
146
146
146
146
147
147
147
147
148
148
148
148
148
149
149
149
150
150
151
152
152
153
153
153

153
154
155
155
155
156
157
158
158
158
159
159
160
160
xiv
16
17
18
Part
Ill
1
2
3
Heterocyclic Chemistry
1,2,5-Thiadiazoles
Synthesis
Physical Properties
Physical Properties
Chemical Properties
2,1,3-Benzothiadiazoles and 2,1,3 -Benzoselenadiazoles

1,2,5-Thiadiazol0[3,4-g]benzofurazan
Dithiazoles and Diselenazoles
1,2,3-Dithiazoles
1,2,4-Dithiazoles
1,3,2-Benzodithiazoles
1,4,2-Dithiazoles
1,2,4-Diselenazoles
Oxathiazoles and Selenathiazoles
1,2,3-0xathiazoles
1,3,2-Oxathiazoles
1,2,4-0xathiazoles
1,3,4-Oxathiazoles
1,3,5-Oxathiazoles
1,2,4-Thiaselenazoles
Miscellaneous Ring Systems
1,2,3,4-Thiatriazoles
1,2,3,5 -Dithiadiazoles
1,3,2,4-Dioxathiazoles
Other Five-membered Ring Systems
ByG.
K
Boyd
Introduction
Reviews
Systems with One Heteroatom, and their Benzo-analogues
Furans
Formation
Reactions
Benzofurans
Formation

Reactions
Formation
Reactions
Formation
Reactions
Pyrroles
Indoles and Carbazoles
Isoindoles
Other Heterocyclic Systems
161
161
161
162
162
162
163
163
163
163
164
164
164
165
165
165
165
166
166
166
166

166
167
167
167
167
168
168
168
168
172
174
174
177
178
178
181
184
184
187
192
193
Contents
xv
4
Systems containing Two Identical Heteroatoms
Dioxoles
1,2-Dithioles
1,3-Dithioles
Tetrathiaf ulvalenes
A Diselenole

Pyrazoles
Formation
Reactions
Indazoles
Imidazoles
Formation
Reactions
Benzimidazoles and other Annelated Imidazoles
5
Systems containing Two Different Heteroatoms
Oxathioles and Oxaselenoles
Isoxazoles
Formation
Reactions
Benzisoxazoles
Oxazoles
Formation
Reactions
Benzoxazoles
Other Systems
Trithiolans
1,2,3-Triazoles and Benzotriazoles
1,2,4-Triazoles
Oxadiazoles
6
Systems containing Three Identical Heteroatoms
7
Other Systems containing Three Heteroatoms
1,2,3-0xadiazoles
1,2,4-0xadiazoles

1,2,5-0xadiazoles
1,3,4-Oxadiazoles
1,2,3-Thiadiazoles
1,2,4-Thiadiazoles
A 2,1,3-Benzothiadiazole
1,3,4-Thiadiazoles
1,2,3-Selenadiazoles
Other Selenadiazoles
Thiadiazoles
Selenadiazoles
Other Systems in which Two
of
the Three Heteroatoms
Systems containing Three Different Heteroatoms
are Identical
193
193
194
197
199
200
20
1
201
201
204
205
205
205
208

209
209
211
211
213
215
2 16
216
217
219
220
220
220
220
222
223
223
223
224
225
226
226
226
227
228
228
228
228
229
229

232
xvi
Heterocyclic Chemistry
8
Systems containing Four Heteroatoms
Tetrazoles
1,2,3,4-ThiatriazoIes
Miscellaneous Systems
Rings
(5,5)
Systems containing Oxygen and/or Sulphur
Nitrogen Systems
9
Compounds containing Two Fused Five-membered
Monoaza-compounds
Diaza-compounds
Triaza-compounds
Tetra-aza-compounds
Penta- and Hexa-aza-compounds
Mixed Oxygen, Nitrogen Systems
Other Mixed Systems
Rings
(5,6)
Nitrogen Systems
10
Compounds containing Fused Five- and Six-membered
Monoaza-compounds
Diaza-compounds
Triaza-compounds
Tetra-aza-compounds

Penta- and Poly-aza-compounds
Compounds containing Oxygen and Nitrogen
Other Mixed Systems
11
Compounds containing Fused Five- and Seven-
membered Rings
(5,7)
Nitrogen Systems
Monoaza-compounds
Diaza-compounds
Triaza-compounds
Tetra- and Penta-aza-compounds
Other Systems
Chapter
4
Six-membered
Ring
Systems
By
G.
P.
Ellis
and
R.
K.
Smalley
Part
I
Azines, Oxazines, and Thiazines
By

R.
K.
Smalley
1
Reviews
2
Azines and their Hydro- and Benzo-derivatives
Pyridines
Synthesis
Reactions
232
232
233
234
235
235
236
236
237
239
239
239
240
241
242
242
242
243
245
247

249
250
252
252
252
252
253
254
254
255
257
257
257
258
258
258
263
Con
ten
fs
xvii
Hydro-p yridines
275
Quinoline, Isoquinoline, and their
Benzo-
and Hydro-
derivatives
282
3
Diazines and their Hydro- and Benzo-derivatives

293
Pyridazines, Cinnolines, and Phthalazines
293
Pyrimidines and Quinazolines
296
Pyrazines and Quinoxalines
304
Purines, Pteridines, and Related Systems
308
Other Systems with
Two
Nitrogen Atoms
316
4
Triazines and Tetrazines
320
5
Oxazines, Thiazines, and their Benzo-derivatives
6
Oxa- and Thia-diazines and Related Systems
323
327
Part
II
Other Six-membered
Ring Systems
By
G.
P.
Ellis

1
Books and Reviews
2
Systems containing One Oxygen
or
Sulphur
Atom
Reduced Pyrans
Pyrans
Pyrones
Preparation
Properties
Pyrylium salts
Thiop yrans
Synthesis
Reactions
Chromans
Isochromans
Chromenes
Chromanones
Chromones
Thiochromans, Thiochromenes, Thiochromanones,
Flavans and Isoflavans
Isoflavenes
Flavanones
Isoflavanones
Flavones
Isoflavones
Dihydrocoumarins
Coumarins

Isocoumarins
Thiocoumarins
Xanthenes
Thiochromones
329
329
330
330
332
333
333
336
337
340
340
34
1
34
1
343
344
345
346
349
350
350
351
352
353
356

358
358
362
363
363
and
xviii
Heterocyclic Chemistry
Thioxanthenes
Xanthones
3
Systems containing Two
or
More Oxygen
or
Sulphur
Atoms
Oxathians and their Benzo-derivatives
Dioxans and Benzodioxans
Dithians and Related Compounds
Systems consisting
of
Two
or More Oxygen-containing
Rings
Cannabinoids
Rotenoids
Other Natural Compounds
Synthetic Compounds
Systems containing Oxygen and Sulphur in Different Rings

4
Systems containing Phosphorus as
a
Heteroatom
5
Systems containing Silicon
or
Selenium
as
Heteroatoms
Chapter
5
Seven-membered Ring Systems
By
D.
J.
Le
Count
1
Introduction
2
Reviews
3
Systems containing One Heteroatom
One Nitrogen Atom
One Oxygen Atom
One Sulphur Atom
Other Systems
4
Systems containing Two Heteroatoms

Two
Nitrogen Atoms
Nitrogen and another Heteroatom
0
t her Systems
5
Systems containing Three
or
More Heteroatoms
Chapter
6
Eight-membered and Larger Ring Systems
By
G.
M.
Brooke
1
Eight-membered Rings
One Heteroatom
Two
Heteroatoms
Three or More Heteroatoms
2
Nine- and Ten-membered Heterocycles
364
365
3 67
367
368
370

370
370
371
372
374
374
375
375
377
377
377
377
377
389
392
395
395
395
405
408
410
411
411
41
1
412
414
416
Contents
3

Macrocycles
Systems containing Nitrogen only
One Nitrogen Atom
Two
or Three Nitrogen Atoms
Four Nitrogen Atoms
Five or More Nitrogen Atoms
Systems containing Nitrogen and Other Heteroatoms
Systems containing Heteroatoms other than Nitrogen
Crown Ethers and Related Compounds
Syntheses
Effects on Chemical Reactions
Reactions
of
the Macrocyclic Rings
Formation
of
Host-Guest Complexes
Chapter
7
Bridged
Systems
By
J.
M.
Mellor
1
Introduction
2
Reviews

3
Physical Methods
X-Ray and Neutron Diffraction
Photoelectron Spectroscopy and Related Electrochemical
Nuclear Magnetic Resonance Spectroscopy
Electron Spin Resonance Spectroscopy
Miscellaneous
Studies
4
Nitrogen Compounds
Synthesis
xix
419
419
419
420
422
424
425
426
429
429
430
432
434
439
439
439
440
440

442
444
445
445
445
445
Tropane Derivatives and Related Azabicyclo[3.2. lloctanes 446
Other Alkaloid Syntheses 449
Cycloadditions 450
Cyclizations with Nucleophilic Nitrogen 455
Cyclization
via
Radical Intermediates 456
Cyclization
via
Electrophilic Nitrogen 456
Reactions 457
Bridged Azoalkanes 458
5
Oxygen Compounds
459
Cycloadditions
459
Miscellaneous Syntheses 461
Bridged Peroxides 462
6
Sulphur Compounds
463
Cycloadditions 463
Miscellaneous Syntheses 464

xx
Heterocyclic Chemistry
7
Bridged Annulenes and Related Systems
8
Cyclophanes
9
Cryptands and Cryptates
Chapter
8
Conformational Analysis
By
F.
G.
Riddell
1
Introduction
2
Four-membered Rings
3
Five-membered Rings
4
Six-membered
Rings
Oxygen-containing Rings
Nitrogen-containing Rings
Sulphur-containing Rings
Phosphorus-containing Rings
Boron- and Silicon-containing Rings
5

Seven-membered Rings
6
Eight-membered
Rings
7
Nine-membered and Larger Rings
8
Polycyclic Systems
464
464
466
469
469
469
470
470
470
472
476
478
480
481
48
1
482
484
Author Index
489
1
Three-membered

Ring
Systems
BY
T.
J.
MASON
The last Report on three-membered heterocyclic rings to appear in one
of
the
Specialist Periodical Reports series concerned only saturated systems and
covered material published in 1975.l The scope
of
this Report has been extended
to include unsaturated systems, and some articles published between 1975 and
the current review have been included here to attempt to bridge the gap
in
coverage.
1
Oxirans
Preparation Catalytic Oxidation
of
Alkenes
to Oxirans,
using Oxygen
or
Oxy
-
gen-containing Gases.
The use
of

supported silver catalysts for the gas-phase
epoxidation
of
ethene continues as an area
of
active investigation. Improvements
in the selectivity of the reaction may be attained by doping the silver with trace
quantities of other metals;
e.g.,
0.2 atom
O/O
of
Na or
K,
or
0.003%
of
Cs
or Rb,
increase selectivity to around
~OO/O.~
Selectivity may also be improved by the
addition of 1,2-dichloroethane to the gases; this retards the formation of
CO,
and
H20.
It is reported that
HCI
(produced by the dehydrochlorination
of

the
chloro-alkane) reacts with chemisorbed atomic oxygen on the silver catalyst to
form chemisorbed atomic ~hlorine.~ The kinetics
of
such a reaction, in the
presence of dichloroethane, have been reported, and rates of both oxidation and
epoxidation depend on the concentrations of ethene and ~xygen.~
The
palladium complex
[PdCl,{P(C,F,),},]
has
been found to give a selectivity
of more than
60%
in the epoxidation
of
~ropene.~
A
mixtiire of 43.1% propene,
54.4%
hydrogen, and
2.5%
oxygen was passed through the catalyst in
1,2-
dichlorobenzene and water at
67
“C
and 15.8 atm pressure; no carbon dioxide
was formed.
Photosensitized epoxidation has received considerable attention over the past

few years. Since 1974, many cases have been reported in which photo-epoxida-
T.
J.
Mason, in ‘Saturated Heterocyclic Chemistry’, ed. G. Pattenden, (Specialist Periodical
Reports), The Chemical Society, London,
1978,
Vol.
5,
p.
1.
W.
D.
Mross,
E.
Titzenthaler, M. Schwarzmann, and
J.
Koopman, Ger. Offen.
2 704 197
(Chem.
Ah.,
1978,89, 163 381).
P.
Kripylo, L. Gerber,
P.
Muench,
D.
Klose,
and L. Beck, Chem. Tech. (Leiprig)
1978,
30,

630
(Chern.
Abs.,
1979,90,103 080).
A.
Gawdzik and
J.
Wasilewski, Chem.
Stosow.,
1978,22,13
(Chem.
Abs.,
1978,89 89 924).
’
P.
N.
Dyer, Ger. Offen.
2 746 812
(Chem.
Abs.,
1978,89,43 091).
1
2
Heterocyclic Chemistry
tion competes with the usual reactions of singlet oxygen,6 the reaction being
influenced by, among other factors, the nature of the photosensitizer.' An
example is the reaction of bisadamantyl with oxygen in acetone solvent; sensi-
tization by methylene blue yields more than
95%
of

1,2-dioxetan whereas more
than
95%
of the epoxide is formed with rose bengal as sensitizer. The photo-
oxygenation
of
a-pyronene
(1)
with tungsten lamps using methylene blue yields
peroxide (2), which may be reduced by Ph3P, in a low-yield reaction, to the
epoxide
(3).8
The epoxide
(4)
is directly produced by oxidation of
(1)
with
perbenzoic acid. Dimethylstyrene
(5)
and tetraphenylporphine (a dye photosen-
sitizer), when irradiated in CCl, using sodium lamps, react with oxygen to give a
mixture
of
products containing
30%
benzene gave epoxide
(7)
(65%).'
of
the diperoxide

(6),
which on refluxing in
r7J-f
\
om
0°0
0
The cleanest photo-epoxidations occur using a-diketones as sensitizers.
lo
The
mechanism of the reaction has been investigated by Bartlett, using
for
the
epoxidation of norbornene." With benzil
or
biacetyl as sensitizers, the results
suggested the intermediacy of a diradical species such as
(8;
R
=
Me or Ph) in the
reaction. Attempted photo-epoxidation
of
vinyl-allenes using biacetyl as sensi-
tizer yielded little or no epoxide, but resulted in a good and efficient method
of
converting such compounds into cyclopentenones.12 The yields
of
cyclo-
pentenones

(10)
isolatedfrom the allenes
(9;
R1
=
But,
R2
=
H),
(9;
R'
=
C5Hll,
R2
=
H),
and
(9;
R'
=
C4H9,
R2
=
H)
being
40,
55,
and
6O%,
respectively.

A
mechanistic investigation of the
acenaphthenequinone-sensitized
photo-
epoxidation
of
alkenes has been rep0~ted.l~ Photolysis of the quinone in
dichloromethane that was continuously saturated in oxygen generated
1,s-
naphthalic anhydride in
80%
isolated yield. When cyclohexene was included in
P.
D.
Bartlett and
M. S.
Ho,
J.
Am. Chem.
SOC.,
1974,96,627.
C.
W.
Jefford and
A.
F.
Boschung, Helu.
Chim.
Ada,
1977,60, 2673.

W.
Cocker,
K.
J.
Crowley,
and
K.
Srinivasan,
J.
Chem.
Soc.,
Perkin
Trans.
1,
1978, 159.
M.
Matsumoto and
K.
Kuroda, Japan. Kokai
78 68 789
(Chem. Abs.,
1978,89, 197 559)
lo
N.
Shimizu and
P.
D.
Bartlett,
J.
Am. Chem.

SOC.,
1976,98,
4193.
l1
P.
D.
Bartlett and
3.
Becherer,
Tetrahedron
Lett.,
1978,2983.
l2
M.
Malacria and
J.
Gore,
J.
Org.
Chem
1979,44,885.
l3
J-Y. Koo and
G.
B. Schuster,
J.
Org.
Chem.,
1979,44, 847.
Three-membered

Ring
Systems
3
the reaction solution it was converted into a mixture
of
oxidized products
consisting mainly
of
allylic hydroperoxide
(40%)
and epoxide
(33%).
A
possible
(8)
(9)
(10)
mechanism was proposed (Scheme
1)
involving the diradical intermediate
(1 1)
obtained by either
C-
or O-oxidation. It was suggested that this intermediate
could yield
O3
by further reaction with
O2
and thus account for the small amount
of

adipaldehyde formed in the reaction.
a*
\/
.?I
0-0'
4%
I
0'
/
0
a
\/
Scheme
1
Oxidation
of
Alkenes
to
Oxirans by Peroxy-acids.
The use of peroxy-acids
in
the
epoxidation
of
unsaturated compounds has been re~iewed.'~ Vinyloxiran
(12)
was prepared
in
95%
yield by the reaction

of
peroxypropanoic acid with
butadiene
in
benzene at
40
OC.15 The same peroxy-acid, continuously generated
by the reaction
of
propanoic acid with hydrogen peroxide, has been used in the
'*
E.
L.
Gershanova,
E.
I.
Stratonova, M. F. Sorokin, and
Z.
A.
Mikhitarova, Deposited Document
l5
G. Rauleder,
H.
Seifert,
H.
Waldmann, W. Schwerdtel, and W. Swodenk. Ger. Offen.
2
734
242
1976,

VINITI
792
(Chem.
Ah.,
1978,88,61683).
(Chem.
Ah.,
1979,90,
168
429).