As part of an effort to understand the chemistry of cyclopropylidenoid ring opening in solution, the enantiomeric ratio of resulting allenes have been measured by nuclear magnetic resonance;When treated with methyllithium, at various temperatures, using ether as the solvent, optically pure 1,1-dibromo-trans-2,3-diphenylcyclopropane yields 1,3-diphenylallene with about 60% enantiomeric excess;The base induced decomposition of optically pure ethyl-N-nitroso-N- (trans-2,3-diarylcyclopropyl) carbamates yields allenes with about 45% enantiomeric excess;From the relative enantiomeric excess of the allenes from these two methods, we conclude the ring opening of halolithiocyclopropyl is different and may have more carbene character at the product forming stage.