Direct and Selective Syntheses of α,α-Dichloroethyl Ketones or Their Ethyl Trimethylsilyl Mixed Acetals by the Reactions of Methoxymethyl or Ethyl Carboxylates with 1,1-Dichloroethyllithium in the Presence of Chlorotrimethylsilane
作者:Isamu Shiina、Yumiko Imai、Masahiko Suzuki、Manabu Yanagisawa、Teruaki Mukaiyama
DOI:10.1246/cl.2000.1062
日期:2000.9
generated by treating 1,1-dichloroethane (2) with lithium diisopropylamide (LDA) or n-butyllithium, reacted with methoxymethyl carboxylates in the coexistence of chlorotrimethylsilane (3) to afford the corresponding α,α-dichloroethyl ketones in good yields. On the other hand, 1 reacted with ethyl carboxylates under the above reaction conditions to give 2,2-dichloro-1-alkyl-1-ethoxy-1-(trimethylsiloxy)propanes
1,1-二氯乙基锂 (1),通过用二异丙基氨基锂 (LDA) 或正丁基锂处理 1,1-二氯乙烷 (2) 生成,在三甲基氯硅烷 (3) 共存下与甲氧基甲基羧酸盐反应,得到相应的 α,α -二氯乙基酮,收率良好。另一方面,1在上述反应条件下与羧酸乙酯反应,以良好的产率选择性地得到2,2-二氯-1-烷基-1-乙氧基-1-(三甲基甲硅烷氧基)丙烷。