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SYNTHESIS OF SOME NEW SUGAR BASED 3, 3-DISUBSTITUTED MONOCYCLIC آ-LACTAMS BY ASYMMETRIC [2+2] CYCLOADDITION REACTIONS

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Synthesis of some new monocyclic beta-lactams containing a quaternary carbon center via a [2+2] cycloaddition reaction is described. The reaction of achiral diphenyl ketene with chiral aldimines derived from chiral 2, 3, 4, 6-tetra-O-acetyl-beta-D-galactopyranosylamine, 2, 3, 4, 6-tetra-O-acetyl-beta-D-glucopyranosylamine and different benzaldehydes resulted in the formation of beta-lactams as single diastereomers.

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