Abstract
Thermal reactions of (2R, 5S, 6S)-2-(1-methylethenyl)-6-phenylacetamido-4-oxa-1-azabicyclo [3.2.0] heptane-3, 7-dione (1) with alcohols gave 2-phenylmethyl-4-{N-[(1R)-1-carboxy-2-methylprop-2-enyl] carbamoyloxazole (2a), (3S, 4S)-4-alkoxy-1-[(1R)-1-carboxy-2-methylprop-2-enyl]-3-phenylacetamidoazetidin-2-ones (3a, c), and (2S)-N-[(1R)-1-carboxy-2-methylprop-2-enyl]-3, 3-dialkoxy-2-phenylacetamidopropionamides (4a, c), probably via an intramolecular ring transformation of 1 into (1S, 5R)-3-phenylmethyl-6-[(1R)-1-carboxy-2-methylprop-2-enyl]-4-oxa-2, 6-diazabicyclo [3.2.0] hept-2-en-7-one (5a) in the initial stage of the reaction.
