| 摘要 |
A process for preparing a 3-exomethylenecepham sulfoxide ester of the formula 2; …<CHEM>… wherein R is the residue of a carboxylic acid and R1 is a carboxylic acid protecting group, which process comprises:… (a) mixing under anhydrous conditions in an inert organic solvent a 2-chlorosulfinylazetidin-4-one of the formula 1: …<CHEM>… with stannic chloride in the presence of an oxygen compound selected from the group consisting of …<CHEM>… |
