<i>N</i>-Bromosuccinimide (NBS) Catalyzed Highly Chemoselective Acetalization of Carbonyl Compounds Using Silylated Diols and Pentaerythritol under Neutral Aprotic Conditions
作者:Babak Karimi、Hassan Hazarkhani、Jafar Maleki
DOI:10.1055/s-2004-837291
日期:——
Various types of carbonyl compounds are efficiently convened to their 1,3-dioxanes and pentaerythritol diacetals by the use of either 1,3-bistrimethylsiloxy propane (A) or 1,3-bistrimethylsilanyloxy-2,2-bistrimethylsilanyloxymethyl propane (D) and a catalytic amount of N-bromosuccinimide (3-10 mol%) under essentially neutral aprotic condition, respectively. A variety of functionalities such as both
通过使用 1,3-双三甲基甲硅烷氧基丙烷 (A) 或 1,3-双三甲基硅烷氧基-2,2-双三甲基硅烷氧基甲基丙烷 (D) 和分别在基本中性非质子条件下催化量的 N-溴代琥珀酰亚胺 (3-10 mol%)。在目前的反应条件下,脂肪族和酚类-OTBDMS、-OMe、-OBz、呋喃环、双键和更显着的酚类-OTHP 等多种官能团仍然存在。使用本协议还实现了两种 α-叔酮向其环状缩醛的有效转化。