Synthesis of (+/-)-4-De(3'-hydroxypropionyl)betaenone B, an Advanced Model for the Betaenones and Stemphyloxin I

Article abstract of DOI:10.1021/jo00260a017

A stereocontrolled synthesis of (+/-)-3, a model for the stereochemically complex naturally occurring phytotoxins 1, 2, and 6, is reported.The synthesis relies upon the steric bias of a cis decalone skeleton for the establishment of appendage stereochemistry.The tricyclic bromo enone 9 prepared in five steps from methoxybenzoquinone was converted in nine steps to the dione 37.Ten additional steps were required to transform 37 to cis decalone 48.As predicted by molecular mechanics calculations, the cis decalone 48 was equilibrated essentially quantitatively to trans decalone 49 on exposure to base.Deprotection of 49 afforded (+/-)-3, the structure of which was proven by single-crystal X-ray analysis.