EFFICIENT STEREOSELECTIVE SYNTHESIS OF ALL GEOMETRICAL ISOMERS OF HEPTADECA-11,13-DIENES

摘要

All geometrical isomers of heptacosa-11,13-dienes, 1-4, previously identified in termite Prorhinotermes simplex cuticular hydrocarbons, were efficiently synthesized according Peterson-Hudrlik olefination procedure in high stereoisomeric purity using syn and anti elimination of erythro alkenyl-beta-hydroxysilanes (15 and 17). These (Z)- and (E)-alkenyl-beta-hydroxysilanes are available from regioselective opening of (1R*,2S*)-1,2-epoxy-1-trimethylsilylpentadecane 13 with corresponding (Z)- and (E)-dodec-1-enyl cuprates (14 and 16). Stereoisomeric purity of obtained dienes 1-4 was higher than 95% (C-13 NMR). [References: 12]