A FACILE ENTRY TO 3-(1-HYDROXYETHYL)-2-AZETIDINONES FROM METHYL (R)-3-HYDROXYBUTANOATE BASED ON THE ESTER ENOLATE-ALDIMINE CONDENSATION

Abstract
The reaction of the dianion of methyl (R)-3-hydroxybutanoate with the N-silylimine generated from trimethylsilylpropynal afforded (3R,4S)-3-[(R)-1-hydroxyethyl]-4-trimethylsilylethynyl-2-azetidinone as the major product, of which the stereochemistry was assigned through its stereospecific conversion to the (+)-4-acetoxy derivative.