Intermolecular Reactions of Chlorohydrine Anions: Acetalization of Carbonyl Compounds under Basic Conditions
作者:Michał Barbasiewicz、Mieczysław Ma̧kosza
DOI:10.1021/ol0613113
日期:2006.8.1
[reaction: see text] Nonenolizable aldehydes and ketones react with 2-chloroethanol and 3-chloropropanol under basic conditions (t-BuOK, DMF/THF) with formation of 2-substituted 1,3-dioxolanes and 1,3-dioxanes, respectively. Conversion of the two-step addition-alkylation process depends on the electrophilicity of the carbonyl group that governs the equilibrium of addition of chloroalkoxides. This method
[反应:见正文]不可烯化的醛和酮在碱性条件下(t-BuOK,DMF / THF)与2-氯乙醇和3-氯丙醇反应,分别形成2-取代的1,3-二氧戊环和1,3-二氧六环。两步加成烷基化过程的转化取决于控制氯代醇盐加成平衡的羰基的亲电子性。这种在动力学控制的条件下以环状缩醛形式保护羰基的方法是与二醇进行酸催化反应的补充。