in this paper is reported the stereoselectivesynthesis of all-trans-tetraenes by reductive elimination of 1,8-dibenzoate-2,4,6-trienes with sodium amalgam. The method was applied to the syntheses of 4E, 6E, 8E, 10E-heptatetraene and β—parinaric acid methyl ester.
An enantioselective synthesis of (+)-isobretonin A is described. The chiral glycerol moiety was enantioselectively prepared by reduction of an optically active beta-keto sulfoxide. The all-trans trienic part of the molecule was stereoselectively synthesized via reductive elimination of a 1,6-dibenzoate 2,4-diene with sodium amalgam.
Chemistry of polyenic and polyacetylenic compounds