14 nearly quantitative crude yield, and oxidation to ketone 11 was accomplished with activated manganese dioxide. The protecting groups were removed sequentially. The desulfurization reaction of 11 to 12 was accomplished with Raney nickel and required a 1O: l ratio by weight of metal to substrate to carry out the reaction at room temperature. However, if heated to reflux in ethanol a single product was obtained in which the carbonyl was ...
