Synthetic Studies Directed toward Cembranolides. Synthesis of the Basic Nucleus of Crassin Acetate

Article abstract of DOI:10.1021/jo00220a018

A stereospecific synthesis of the basic crassin acetate nucleus, erythro-1-(hydroxymethyl)-14-hydroxy-4,8,12-trimethylcyclotetradeca-(E,E,E)-3,7,11-triene, has been achieved.Stereospecific syntheses of the two precursors to this ring system, (E,E)-3,7-dimethyl-9-(phenylthio)nona-3,7-dienal and (E)-2,8-bis(trimethylsiloxy)-2,7-dimethyloct-6-en-3-one, have been developed.These moieties were combined via an aldol condensation to yield erythro-9-hydroxy-10-<1-oxo-2-methyl-2-(trimethylsiloxy)propyl>-1-(phenylthio)-14-(trimethylsiloxy)-3,7,13-trimethyltetradeca-(E,E,E)-2,6,12-triene which, in a series of reactions, was cyclized to the titled 14-membered ring system.