Carbon-14-labeled diethylstilbestrol synthesis by the McMurry method: concurrent formation of hexestrol.

Isotopically labeled diethylstilbestrol prepared from p-methoxypropiophenone by coupling with TiCl3-LiA1H4 contained approximately 50% hexestrol. Nonlabeled preparations and a subsequent labeled preparation had less than 2% hexestrol in them. Initial examinations for purity by gas-liquid chromatography, thin-layer chromatography, and isotope dilution did not show the presence of hexestrol. Specific ion monitoring of a gas chromatography-mass spectrometry determination revealed the presence of the deithylstilbestrol-hexestrol mixture.