New practical synthesis of panomifene. The effect of 2-trifluoromethyl substituent on the stereoselectivity of dehydration of 1,1,2-triarylethanols

Abstract Highly stereoselective eliminations were achieved by acid-catalysed dehydration of 1-(4-alkoxy)-3,3,3-trifluoro-1,2-diphenylpropan-1-ols ( 10, 11, 15 ). The influence of the trifluoromethyl group on the stereochemistry of the elimination has been discussed. The observed high stereoselectivity has been applied to give a new, practical synthesis of antiestrogenic drug panomifene ( 1 ).