Reduction of a 2-(p-tolylsulfinyl)cycloalkanone with sodium borohydride in methanol–triethylamine is accompanied by rapid epimerization at C2. Under the conditions employed here, the π-facial selectivity of the reduction is directed by the side chain chirality and, among four possible isomers of the corresponding cycloalkanol, one isomer is given with high selectivities up to 85%.
用
硼氢化钠在
甲醇-
三乙胺中还原2-(p-
甲苯硫酰基)环烷酮时,C2处会迅速发生表异构化。在这里采用的条件下,减肥的π面选择性受侧链手性影响,在相应的环烷醇的四种可能异构体中,有一种异构体的选择性高达85%。