SYNTHESIS OF (+)-(3S,7S,10S)- AND (+)-(3S,7S,10R)-3,7,10-TRIMETHYLBORATRANE. AMPLIFICATION OF ENANTIOMERIC PURITY IN THE REACTION BETWEEN AMMONIA AND PROPYLENE OXIDE

Article abstract of DOI:10.1016/S0040-4020(01)83483-9

The synthesis is described of the two enantiomerically pure isomers (+)-(3S,7S,10S)- and (+)-(3S,7S,10R)-3,7,10-trimethylboratrane.The structures were determined by 1H- and 13C-NMR spectroscopy.A method for increasing the enantiomeric purity by trimerization reactions of partially-resolved (S)propylene oxide is proposed.The reaction was studied from the kinetic viewpoint and interpreted according to a binomial probability scheme.The experimental findings point to a rapid growth in enantiomeric purity for the (SSS) trimer compared with the starting material, whilst no increase was found for the (SSR) trimer.