Convergent Stereocontrol in Peterson Olefinations. Application to the Synthesis of (±)-3-Hydroxybakuchiol and Corylifolin
作者:Joe B. Perales、Narubumi F. Makino、David L. Van Vranken
DOI:10.1021/jo0259459
日期:2002.9.1
stereospecific sila-Pummerer rearrangement, they made it possible to stereoselectively generate E olefins without isolation or separation of syn- and anti-beta-silyl alkoxides. Addition of a neopentyl alpha-silyl alkyllithium intermediate to an aryl aldehyde generated a mixture of syn- and anti-beta-silyl alkoxides. The syn-beta-silyl alkoxide eliminated stereospecifically at -78 degrees C to give an E olefin, whereas
Bakuchiol derivatives from the leaves of Psoralea glandulosa
作者:Cecilia Labbé、Francesca Faini、Joseph Coll、Joseph D. Connolly
DOI:10.1016/0031-9422(96)00144-6
日期:1996.7
Four new meroterpene derivatives have been isolated in a bioassay-guided study of the methanol extract of the leaves of Psoraleaglandulosa, in addition to the known compounds bakuchiol and angelicin. Structures for the new compounds are proposed on spectroscopic evidence. The results of brine shrimp (Artemia salina) and disc-choice (Spodoptera littoralis) bioassays are interpreted in terms of the