Antioestrogenic and antifertility compounds. II. Synthesis of optically active 2,3-Bis(p-methoxyphenyl)alk-1-enes

Abstract

The enantiomers of 2,3-bis(p-methoxyphenyl)but-1-ene were synthesized by different routes. The laevo isomer, [α]D -73.6º, was derived by conversion of (+)-erythro-2,3-bis(p-methoxyphenyl)butylamine into (+)-erythro-l-N,N-dimethyl- amino-2,3-bis(p-methoxyphenyl)butane, and pyrolysis of the corresponding quaternary hydroxide. The absolute configuration of 2,3-bis(p-methoxyphenyl)but-1-ene was established as (+)-(R) by synthesis of the dextro isomer, [α]D + 72.50º, from (+)-(S)-2-(p-methoxyphenyl)propionic acid via (+)-(S)-3-(p-methoxyphenyl)butan-2-one. It follows that the absolute configuration of (+)-eryihro- 2,3-bis(p-methoxyphenyl)butylamine is (2R,3S). (-)-2,3-Bis(p-methoxyphenyl)pent-1-ene, [α]D -49.5º, was synthesized from (+)-erythro-2,3-bis-(p-methoxyphenyl)pentylamine.