Synthetic studies towards the prostaglandins

The synthesis of an important intermediate (36) in a total synthesis of the prostaglandins was undertaken. Treatment of the monoanion of the pyrrolidine enamine of methyl acetoacetate with cis-4,5-epoxy-2(E)-decen-1-yl mesylate (42) followed by addition of one equivalent of lithium diisopropylamide and then hydrolysis yielded the desired intermediate 36. This intermediate contains the correct relitive stereochemistry between the C-12 and C-15 carbons which has turned out to be the most difficult problem associated with the synthesis of the prostaglandins. Alkylation with trans-4,5-epoxy-2(E)-decen-1-yl mesylate (67) produced the intermediate with the unnatural stereochemistry. The two mesylates were produced stereospecifically, the first starting from propargyl alcohol. In the process of making these two mesylates, two natural products were synthesized, ethyl 2(E),4(Z)-decadienoate (79), isolated from Bartlett pears, and 2(E),4(Z)-decadien-1-yl isovalerate (41), isolated from the essential oils of Cyprus.Science, Faculty ofChemistry, Department ofGraduat