(Z)-Tamoxifen was synthesized from a simple olefin (trans-stilbene) in 5 steps and 40% overall yield (Z/E = 74:26). The phenyl substituted group (4-Me2NCH2CH2OC6H4) was attached by a bromination-dehydrobromination-Suzuki reaction sequence. Subsequently, the ethyl group was attached to the triarylated olefin by a bromination-Negishi reaction sequence. Both the Suzuki and Negishi cross-coupling processes are stereospecific, and the stereoselectivity depends only on the bromination-dehydrobromination reactions. (Z)-Tamoxifen was also obtained from trans-stilbene in only 3 steps by using Heck reaction-bromination-Negishi reaction sequence in 57% overall yield (Z/E = 65:35).
作者:Allan B. Foster、Michael Jarman、On Tai Leung、Raymond McCague、Guy Leclercq、N. Devleeschouwer
DOI:10.1021/jm00148a020
日期:1985.10
contrast to the known 3- and 4-hydroxy derivatives which were obtained as near-equimolar cis,trans mixtures, only the trans forms of the 2-hydroxy, 2-methyl, 2,4-dihydroxy, and 4-hydroxy-2-methyl derivatives were obtained. Also, in contrast to the trans forms of the 3- and 4-hydroxy derivatives, which are readily equilibrated to cis,trans mixtures, the trans 2-hydroxy derivative could not be isomerized