Heterocyclic phosphorous acid chlorides, prepared from C2-symmetric menthyl, borneyl, or fenchyl tartrates and phosphorus trichloride, are inexpensive derivatizing agents for determining the enantiomeric purity of alcohols via phosphorus NMR. The most versatile agent identified from this study, a (1R,2S,5R)-menthyl (R,R)-tartrate-derived 2-chloro-1,3,2-dioxaphospholane, gives, upon esterification with
Lactols in an asymmetric aldol-desymmetrization sequence: access to tetrahydro-4H-furo[2,3-b]pyran-2-one and tetrahydro-4H-furo[2,3-b]furan-2-one derivatives
作者:Ji-Yao Li、Ke-Wei Yu、Chao-Chao Xie、Yan-Kai Liu
DOI:10.1039/c6ob02420c
日期:——
An asymmetric aldol-desymmetrization sequence was developed which provided highly efficient access to important bicyclic oxygen-containing scaffolds with multiple chiral centers and one is a quaternary stereogenic center containing a free hydroxy group. Moreover, starting from racemic precursors, the final products were obtained as two separable diastereomers by flash chromatography. Several other