Resolution of racemic aryl dichloromethyl sulfoxides with (-)-menthone

Article abstract of DOI:10.1016/j.tetasy.2009.08.031

The addition reaction of the sodium α-sulfinyl carbanion of a racemic aryl dichloromethyl sulfoxide to (-)-menthone in the presence of boron trifluoride diethyl etherate gave an adduct as a mixture of two easily separable diastereomers. After separation of the diastereomers, they were each treated with sodium hydride to afford enantiomerically pure aryl dichloromethyl sulfoxides and (-)-menthone both in high yields. This procedure provides a simple and efficient method for the resolution of racemic aryl dichloromethyl sulfoxides.