Chemistry of O-Silylated Ketene Acetals: An Efficient Synthesis of Carbapenem and 1β-Methylcarbapenem Intermediates
3-(1-tert-Butyldimethylsiloxyethyl)-4-phenylsulfinylazetidin-2-one reacted smoothly with various types of O-silylated ketene acetals and silylated enol ethers in the presence of a catalytic amount of zinc iodide to give the corresponding trans-4-substitut