These reactions likely involve protonation of the hydroxyl groups by the catalyst, loss of water to form the stabilized 1,1-diarylethyl carbocations, and deprotonation to complete the elimination. Following these conversions, we sought to use apply this chemistry in the synthesis of a pharmaceutical intermediate for the anti-estrogen drug, tamoxifen (eq 9). Alcohol 28 was prepared using a published route from 1,2-diphenyl-1-butanone and 4-methoxyphenyl magnesium bromide. 11 As with the previous elimination conversions, the alcohol (28) and CH2Cl2 solution gave a high yield of the triaryl alkene (29) when passed through the ABS-SO3H printed catalyst. The product alkene 29 was obtained in a 94% yield as a 1:1 mixture of the E:Z stereoisomers. Analysis of the crude product mixture showed complete conversion to the alkene. The E:Z mixture of compound 29 has been previously converted to tamoxifen. 11