Chiral version of the Burgess reagent and its reactions with oxiranes: application to the formal enantiodivergent synthesis of balanol.

An efficient formal synthesis of a (-)-balanol intermediate ( 25a) from cyclohexadiene oxide was accomplished in eight steps. An asymmetric version of the Burgess reagent allows for an enantiodivergent approach to both enantiomers of balanol from a racemic starting material.