Factors affecting facial selectivity in the hydroboration of steroidal Delta(5)-alkenes


Arantes S., Hanson J., Liman M., Manickavasagar R., UYANIK C.

JOURNAL OF CHEMICAL RESEARCH-S, no.9, pp.530-531, 1998 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: Issue: 9
  • Publication Date: 1998
  • Doi Number: 10.1039/a803403f
  • Title of Journal : JOURNAL OF CHEMICAL RESEARCH-S
  • Page Numbers: pp.530-531

Abstract

A comparison between the alpha- and beta-facial selectivity observed in the hydroboration of some androst-5-enes and beta-norandrost-5-enes does not parallel the difference between the calculated force field energies for alpha- and beta-cyclobutane models suggesting that the facial selectivity is not determined by the four-centre transition state but by the relative ease of formation of the initial pi-complex between the alkene and the borane.