When treated with potassium t-butoxide in dimethyl sulfoxide (KtBD) 2 at room temperature, 24-cholanyl tosylate yielded predominantly the t-butyl ether, as might be expected from previous work. a 24-ChIorocholane, however, surprisingly reacted with KtBD to give mainly the elimination product, 23-cholene. The strikingly unexpected difference between tosylate and corresponding chloride led us to investigate further reactions on 2kiodocholane and ...