“4,7-lactams”, intermediates for penems synthesis. II. Total synthesis of (+)-2,2-dimethyl-9-oxo-3-oxa-6-thia-1-azabicyclo [5.2.01,7]nonane

Abstract The total synthesis of chiral “4,7-lactam” 4 has been accomplished starting from 4-acetoxyazetidinone. An independent route from methyl penicillanate has been used to test the efficiency of the foregoing synthesis.