SYNTHESIS OF A BUTYROLACTONE PRECURSOR OF AN ALGAE NONAETHER FROM AN ENANTIOPURE GLYCOL OBTAINED BY HOPPES CHEMISTRY

Homoallyl carbamate 20, (-)-sparteine, and sBuLi gave a lithium deriva tive which was formylated with DMF giving the crude aldehydocarbamate 19. With Lithium aluminum hydride in refluxing THF, this compound prov ided diol 22 in 90% overall yield and with 96% ee. This material was c arried on to the gamma-lactone monoethers 13 (benzyl ether) or 14 (tri tyl ether). These compounds should be precursors for synthesizing the naturally occurring nonaether 7.