Enantioselective functionalization of prochiral diols via chiral spiroketals: preparation of optically pure 2-substituted 1,3-propanediol derivatives and asymmetric synthesis of chroman ring and side chain of .alpha.-tocopherol
Enantioselective functionalization of prochiral diols via chiral spiroketals: preparation of optically pure 2-substituted 1,3-propanediol derivatives and asymmetric synthesis of chroman ring and side chain of .alpha.-tocopherol
A stereospecific synthesis of (R,R)-phytol uith highly stereochemioal purity in both absolute and geometrical aonfigurations uas achieved by utilizing the SNZ type ring-opening reaction of (R)-β-methyl-β-propiolactone, and the SNZ′ type ring-opening reaction of isopropenyl oxirane, from (R)-pulegone as a starting material.
利用(R)-β-甲基-β-丙内酯的S N Z型开环反应实现的(R,R)-植物甾醇的立体定向合成,无论是绝对构型还是几何构型都具有高度立体化学纯度。异丙烯基环氧乙烷的N Z'型开环反应,以(R)-普来高酮为原料。