Benzylpenicillin sulfoxide

The Control of Protic Acids. There are a number of examples where protic acids have been shown to have a deleterious effect on reactions and where partial or complete control is advantageous. The rearrangement of the benzylpenicillin sulfoxide to the cephalosporanic acid derivative (eq 16) gave the best yield using hydrogen bromide and ca. 30 mol % of BSA. Similarly, the preparation of eight-membered oxygen heterocycles that are... 

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