Iterative Assembly of Chiral Alcohols Utilizing CMMP-Mediated Mitsunobu Reactions

An iterative assembly of chiral alcohol building blocks is reported utilizing cyanomethylene trimethylphosphorane (CMMP)-mediated Mitsunobu reactions. 1,3-Benzodithiole tetraoxide (BDT) was used as the platform to prepare long-chain saturated compounds with multiple stereocenters en route to polyisoprenoid natural products. Selectively protected chiral 1,3-butanediols played a key role in iterative chain elongation for the construction of 1,5-dimethyl branched arrays with high stereocontrol.