<i>C</i><sub>2</sub>-Symmetric Bis-sulfoxide: A Novel Chiral Auxiliary for Asymmetric Desymmetrization of Cyclic <i>m</i><i>eso</i>-1,2-Diols
作者:Naoyoshi Maezaki、Atsunobu Sakamoto、Noboru Nagahashi、Motohiro Soejima、Ying-Xia Li、Tsuneaki Imamura、Naoto Kojima、Hirofumi Ohishi、Ken-ichi Sakaguchi、Chuzo Iwata、Tetsuaki Tanaka
DOI:10.1021/jo9919409
日期:2000.6.1
to be an efficient chiral auxiliary for asymmetric desymmetrization of cyclic meso-1,2-diols via diastereoselective acetal fission. Both (R,R)- and (S,S)-1 are readily synthesized with high optical purity via asymmetric oxidation of 1, 5-benzodithiepan-3-one (2). After acetalization of meso-1,2-diols 6a-e and a mono-TMS ether 6f with this chiral auxiliary 1, the resulting acetals 7a-f were subjected
一种新的杂环化合物,C(2)对称双亚砜1,已被发现是一种高效的手性助剂,可通过非对映选择性缩醛裂变对环状meso-1,2-二醇进行不对称脱对称。(R,R)-和(S,S)-1都可以通过1,5-苯并二硫醚-3-酮(2)的不对称氧化而以高光学纯度合成。用该手性助剂1将内消旋1,2-二醇6a-e和单-TMS醚6f缩醛化后,将所得缩醛7a-f在用六甲基二硅叠氮化钾(KHMDS)处理后,进行碱促进的缩醛裂变。乙酰化或苄基化得到具有高非对映选择性的去对称的二醇衍生物8a-f。手性助剂1易于通过酸促进的水解除去,并且可以在不损失对映体过量的情况下被回收。