Asymmetric Intramolecular [2 + 2] Photocycloadditions: α- and β-Hydroxy Acids as Chiral Tether Groups
作者:Sophie Faure、Sylvie Piva-Le-Blanc、Cyrille Bertrand、Jean-Pierre Pete、René Faure、Olivier Piva
DOI:10.1021/jo001631e
日期:2002.2.1
Chiral alpha- and beta-hydroxy acids such as (S)-lactic acid, (S)-phenyllactic acid, (S)-mandelic acid, or (3R)-3-hydroxybutyric acid have been used as tether groups for intramolecular and diastereoselective [2 + 2] photocycloaddition of 3-oxocyclohexene carboxylic acid derivatives. Total regiocontrol toward the straight adduct and high diastereoselectivities (up to 94%) were observed in the case of
手性α-和β-羟基酸,例如(S)-乳酸,(S)-苯基乳酸,(S)-扁桃酸或(3R)-3-羟基丁酸已被用作分子内和非对映选择性的束缚基团[2 + 2] 3-氧代环己烯羧酸衍生物的光环加成。在乳酸丁烯酯的情况下,可观察到对直加合物的总体区域控制和高非对映选择性(高达94%)。在分离两种非对映异构体后,在碱性条件下裂解手性束缚剂可获得高收率和对映体纯形式的环丁烷内酯。记录了X射线结构,证实了根据CD光谱分配的三个连续的立体中心的相对和绝对构型。