HOMEWORKSBIS22016

<span class='text_page_counter'>(1)</span>HOMEWORKS _ WEEK 2 Problem 1. What is the absolute configuration (R or S) of L-glycreol 3-phosphate? What must be the absolute configuration of the naturally occurring phosphatidic acids biosynthesized from it? Problem 2. Arachidonic acid is the biosynthetic precursor to PGE2. The structures of PGE1 (see Figure 1) and PGE2 are identical except that PGE2 has one more double bond than PGE1. Suggest a reasonable structure for PGE2. O 9. 1. 3. 5. 7. 2. 8. 6. HO COOH. 10. 20. 18 11. 12. 14 13. HO. COOH. 4. 15. CH3. 16 17. CH3. 19. HO. HO. HO Prostaglandin E1 (PGE1  ). Prostaglandin E1 (PGE1). Figure 1. Structures of two representative prosta-gladins. The numbering scheme is illustrated in the structure of PGE1. Problem 3. A synthesis of triacylglycerols has been described that begins with the substance shown. O RCOCH2 CH2OH. CHOCR,. several steps O H3C. O. O CH3. R'COCH2 O. 4-(Hydroxymethyl)2,2-dimethyl-1,3-dioxolane. Triacylglycerol. Outline a series of reactions suitable for the preparation of a triacylglycerol of the type illustrated in the equation, where R and R’ are different. -----------------------------------------------------------------.

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