Steroid organoboranes have been found to be useful synthetic
intermediates. Attempted pyrolyses, based on simple trialkylborane
cyclizations, have not yielded C-19 or C-18 functionalized steroids,
but have produced isomerized systems not otherwise available.
Thus, hydroboration of cholesterol followed by pyrolysis at
215° gives 31% of 2-cholestene-6α-ol and 49% of a...