Total Synthesis of (+)-Aloperine. Use of a Nitrogen-Bound Silicon Tether in an Intramolecular Diels−Alder Reaction
作者:Arthur D. Brosius、Larry E. Overman、Lothar Schwink
DOI:10.1021/ja983013+
日期:1999.2.1
The central element of the synthetic strategy is an intramolecular Diels−Alder reaction in which the cycloaddends are tethered by a N-silylamine linkage. The total synthesis of 1 proceeds from commercially available 3-hydroxypiperidine hydrochloride (54) and (R)-pipecolinic acid (35) by way of nine isolated and purified intermediates. The synthesis is sufficiently efficient that gram quantities of (+)-aloperine
报道了 aperine (1)、N-methylaloperine (2) 和 N-allylaloperine (3) 的对映选择性全合成。合成策略的核心要素是分子内 Diels-Alder 反应,其中环加数由 N-甲硅烷基胺键连接。1 的全合成从市售的 3-羟基哌啶盐酸盐 (54) 和 (R)-哌啶酸 (35) 通过九个分离和纯化的中间体进行。该合成足够有效,可以很容易地制备克量的 (+)-aloperine (1)。早期的探索性研究还引入了一种方便的方法,将环加成伙伴与磺酰胺单元相连,以实现乙烯基磺酰胺的分子内 Diels-Alder 环加成:45 → 46。