A convergent and highly stereoselective formalsynthesis of Pellasoren – A is described. The salient features of the synthesis are the utilization of enzymatic desymmetrization, Crimmin’s non-Evans syn aldol, Lindlar’s and Wittig reaction.
Stereoselective bromination of the E,E-vinylketene silyl N,O-acetal possessing a chiral auxiliary has been achieved and applied to introduction of heteroatom at γ-position of α,β-unsaturated imide. The reactions proceeded in high stereoselectivity. Totalsynthesis of pellasoren A, an antitumor propionate from the myxobacteriun Sorangium cellulosum, has been accomplished in short steps by this methodology