The 7-exo-configuration is assigned to all substituted tricarbonylcycloheptatrienechromiums previously prepared by the “normal” reaction of tricarbonyltropyliumchromium salts with anions. Several new examples are described, and displacement of methoxide from tricarbonyl-7-exo-methoxycycloheptatrienechromium is shown to be an advantageous alternative route to these products.
7-外-构型分配给先前通过三羰基tropylium
铬盐与阴离子的“正常”反应制备的所有取代的
三羰基环庚三烯铬。描述了几个新的实例,并且表明从三羰基-7-外-甲氧基
环庚三烯铬置换
甲醇盐是这些产物的有利替代途径。