Les enols ethers du titre (A) 制备对三氟甲磺酸盐脱三烷基甲硅烷 和 α-重氮乙酰乙酸盐;l'action de l'acetoxy-4 t-丁基二甲基甲硅烷氧基-1'ethyl-3 azetidinone-2 sur les 组成一个导管辅助 α-重氮羟基-1'ethyl-3 oxo-4 azetidineacetylacetates-2
A new process is provided for preparing the key carbapenem intermediates of the formula ##STR1## wherein R.sup.5 and R.sup.6 each independently represent hydrogen or methyl and R.sub.1 represents a conventional carboxyl-protecting group.