acids (R)-(+)-1, (R)-(−)-4 and (S)-(+)-7, respectively, which were obtained from the racemic forms by diastereoisomeric salt separation with homochiral organic bases. The stereomechanism of the hydrolysis reaction of spiro-λ4-sulfanes and sulfonium tetrafluoroborates that depends on pH, the nature of the axial heteroatom, the size of the spiro rings and carboxyl neighbouring group participation is
二芳基(酰
氨基)(酰氧基)螺-λ的立体有择合成4 -sulfanes(小号(+) - - ) 2 ,( - [R )- (+) - 5,(小号) - (+) - 8,和它们的转换分别描述了相关的四
氟硼酸二芳基(酰基
氨基)ulf(R)-(+)- 3,(S)-(+)- 6,(R)-(+)- 9。螺λ的对映异构体4 -sulfanes(小号- ) - (+)2,(- [R )- - (+)5和(小号) - (+) - 8通过的相应的光学活性亚砜-
羧酸(脱
水制备- [R(+) - - ) 1 ,( - [R )- ( - ) - 4和(小号- ) - (+)7,其从得到分别非对映异构体盐与纯手性有机碱的分离得到外消旋形式。螺λ的
水解反应的stereomechanism 4 -sulfanes和锍四
氟硼酸盐取决于pH值,轴向杂原子的性质,螺环和羧基邻基参与的大小进行了讨论。