title: Stereoselective Syntheses of Cis- and Trans-Isomers of alpha-Hydroxy-alpha,beta-dibenzyl-gamma-butyrolactone Lignans: New Syntheses of (+/-)-Trachelogenin and (+/-)-Guayadequiol.
abstract: Cis- and trans-isomers of alpha-hydroxy-alpha,beta-dibenzyl-gamma-butyrolactone lignans 1a,d-g and 2a,c,d were stereoselectively synthesized in good yields based on the electrophilic addition to the metal enolate of alpha-benzyl-gamma-butyrolactone derivatives 1l-o and 3 as a key step. This method was applied to the syntheses of (+/-)-trachelogenin and (+/-)-guayadequiol, representative examples of the trans- and cis-isomers of alpha-hydroxy-alpha,beta-dibenzyl-gamma-butyrolactone lignan series.
authors.affiliation: Lead Optimization Research Laboratory and R & D Planning Division, Tanabe Seiyaku Co., Ltd., 3-16-89 Kashima, Yodogawa, Osaka 532, Japan.
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Moritani
authors.forename: Chiaki
authors.initials: C
authors.lastname: Fukushima
authors.forename: Tatsuzo
authors.initials: T
authors.lastname: Ukita
authors.forename: Toshikazu
authors.initials: T
authors.lastname: Miyagishima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohmizu
authors.forename: Tameo
authors.initials: T
authors.lastname: Iwasaki