Hydroboration. 61. Diisopinocampheylborane of high optical purity. Improved preparation and asymmetric hydroboration of representative cis-disubstituted alkenes

HC Brown, MC Desai, PK Jadhav

Index: Brown, Herbert C.; Desai, Manoj C.; Jadhav, Prabhakar K. Journal of Organic Chemistry, 1982 , vol. 47, # 26 p. 5065 - 5069

Full Text: HTML

Citation Number: 144

Abstract

The convenient preparation of diisopinocampheylborane of high enantiomeric purity (99.1%) utilizing the commercially available relatively stable borane-methyl sulfide and a- pinene of 92% enantiomeric purity is described. Methyl sulfide liberated in the hydroboration step interferes with the equilibration needed to improve the optical purity of the reagent. However, this difficulty is readily overcome by removal of methyl sulfide under vacuum ...