ORGN 588

A highly stereoselective aldol reaction was observed on chromane carboxylate ester 1 via the corresponding diisopinocampheyl boron-enolate using commercially available (-)-DIP-Cl reagent. The aldol product 2c was obtained in 89% yield with 48 dr and 92% ee. Further studies indicate that stereoselective formation of the enolate and proper chiral ligand on boron are responsible for the exceptional diastereo- and enantioselectivity in the aldol reaction.