1 (R = H) is considerably more long-lived (tl12 > 5 min at -100 "C) than its higher homologues. Finally, the course of the reactions of acid anhydrides and chlorides with organolithium reagents is not noticeably altered by the presence of Me,SiCl. The increased rate of collapse of the adduct analogous to 1 generated upon nucleophilic addition to these carbonyl systems apparently precludes their interception by Me3SiC1. In the case of diethyl carbonate ...