Regioselectivity of the Claisen Rearrangement in meta-Allyloxy Aryl Ketones: An Experimental and Computational Study, and Application in the Synthesis of (R)-(−)-Pestalotheol D
作者:Catherine L. Lucas、Barry Lygo、Alexander J. Blake、William Lewis、Christopher J. Moody
DOI:10.1002/chem.201002757
日期:2011.2.7
rearrangement. DFT calculations suggest that the effect is electronic although there is also a steric effect of the bulky silyl group. This strategy for influencing the regiochemical outcome of the Claisen rearrangement was then employed in a short synthesis of the furo[2,3‐g]chromene, (−)‐pestalotheol D, that confirms the absolute stereochemistry of the natural product.
对间烯丙氧基芳基酮的Claisen重排的区域选择性的研究表明,吸电子羰基具有很大的影响力,并将重排直接引导至更受阻的邻位。但是,当酮是环结构的一部分时,可以通过转化成三异丙基甲硅烷基烯醇醚来消除其电子效应,这极大地逆转了克莱森重排的区域化学反应。DFT计算表明该作用是电子的,尽管还有庞大的甲硅烷基的空间作用。然后,在短时间合成呋喃[2,3- g]中采用了影响克莱森重排的区域化学结果的策略。] chromene,(-)-甾醇D,证实了天然产物的绝对立体化学。