Total syntheses of styryl lactones, leiocarpin C and (+)-goniodiol
have been accomplished in a highly stereoselective manner. The key
steps involved in these syntheses are the Chan alkyne reduction,
Sharpless asymmetric dihydroxylation, Horner-Wadsworth-Emmons
olefination, aryl Grignard reaction, hydroboration, stereoselective
alkoxy-directed keto-reduction, stereoselective 1,3-anti-allylation, esterification via ozonolysis,
and intramolecular lactonization.
styryl lactones - dihydroxylation - olefination - hydroboration - 1,3-anti-allylation - ozonolysis