Diastereoselective addition to an α-alkoxyaldehyde under dipolar (Cram–Felkin) and chelation (Cram–cyclic) controlled conditions; a stereocontrolled synthesis of (+)-blastmycinone

Stereoselective synthesis of anti(2) and syn(3) diols by addition of an acetyl anion equivalent to 2-benzyloxypropanal (1) and stereocontrolled synthesis of (+)-Blastmycinone (11) are described.