Investigations on photochemistry of o-allyloxy-/crotyloxyacetophenones: formation of unexpected intramolecular arene–olefin addition products on n–π∗ excitation of ketones
作者:Rajinder Singh、M.P.S. Ishar
DOI:10.1016/s0040-4020(02)00868-2
日期:2002.9
(8a,b), besides some highly unexpected intramolecular arene-olefin addition products (14–16); formation of these intramolecular arene–olefin addition products is quenched in the presence of 0.1 mol equiv. of triethylamine. With increasing molar ratios of triethylamine, in acetonitrile solvent, the formation of 7, 8 is also suppressed with increased formation of products (9–13) derived from photoreduction
已经在不同条件下研究了邻烯丙氧基-/巴豆氧基乙酰苯(6a,b)的光化学。在N 2气氛下(Pyrex过滤器)在干燥的苯中辐照6a,b,导致分离出(syn)-2-乙烯基/丙烯基-3-羟基-3-甲基-2,3-二氢苯并呋喃(7a,b约10%)作为唯一产品。在0.1–0.4 mol当量存在下,在无水苯中辐照6a,b。的三乙胺导致略微增加的形成图7a,b中,除了频哪醇(9和10)和三乙胺加成产物(11和12)。然而,形成图7a,b被抑制随着三乙胺的摩尔比,随着产品(形成增加9 - 13)。在另一方面,照射图6a,b的无水乙腈中都导致形成顺式- (7A,b),以及抗benzodihydrofuranols的异构体(8a中,b),除了一些非常意外的分子内芳烃烯烃加成产物(14 –16); 这些分子内芳烃-烯烃加成产物的形成在0.1摩尔当量的存在下被淬灭。三乙胺。随着三乙胺的摩尔比,在乙腈溶剂中,形成7,8也被抑制随着产品(形成增加9