1,3-Dipolarcycloadditions of azomethine ylides, prepared from 2,2-dimethoxyacetaldehyde, and enantiomerically pure sugar-derived dihydropyranones led to tetrasubstituted pyrrolidines. The cycloadditions were highly regio-, diastereo- and enantioselective, with the endo approach strongly prevailing. The adducts were subjected to hydrolysis and reductions to afford the target 2,3,4,5-tetrahydroxyalkylpyrrolidines
由 2,2-二甲氧基乙醛和对映体纯糖衍生的二氢吡喃酮制备的偶氮甲碱叶立德的 1,3-偶极环加成得到四取代的吡咯烷。环加成反应具有高度的区域选择性、非对映选择性和对映选择性,其中内基法非常普遍。对加合物进行水解和还原,得到目标 2,3,4,5-四羟基烷基吡咯烷。根据烯酮的( R )或( S )立体中心,得到对映体吡咯烷。