Derivation of 3-oxazolin-5-ones from methyl (4S,6S)-5,5,9,9-tetramethyl-7-oxo-8-oxa-4-thia-1-azabicyclo[4,3,0]non-2-ene-3-carboxylate 4-oxide
Abstract
Acetyl chloride converts the lactone sulphoxide (1) into the racemate of the hydroxy-lactone (4) under nitrogen; in the presence of oxygen the 3-oxazolin-5-one (8) is formed by way of the racemate of the hydroxylactone sulphoxide (2).