Department of Chemistry, University of Puerto Rico , Rio Piedras, Puerto Rico 00931-3346, United States.
Org Lett. 2014 Aug 1;16(15):4052-5. doi: 10.1021/ol5019486. Epub 2014 Jul 11.
The first asymmetric γ-alkoxyallylboration of representative ketones provides β-alkoxy tert-homoallylic alcohols 10 whose diastereoselectivities range from 99% syn (acetophenone) to 99% anti (pinacolone) both with high ee (>95%). This distribution is attributable to the c/t isomerization of the BBD reagents and the greater reactivity of 7 vs 1 and of aromatic vs alkyl ketones. A ketone-based direct synthesis of a fostriecin intermediate and the tert-amine 26 are reported, each with high selectivities.
具有代表性的酮的首例不对称γ-烷氧基烯丙基硼化反应提供了β-烷氧基叔同烯丙醇 10,其非对映选择性范围从 99% syn(苯乙酮)到 99% anti(频哪酮),ee 值均大于 95%。这种分布归因于 BBD 试剂的 c/t 异构化以及 7 相对于 1 和芳族酮相对于烷基酮的更高反应性。报道了基于酮的福斯特利辛中间体和叔胺 26 的直接合成,每种方法都具有高选择性。