The Total Synthesis of the Crinine Alkaloid Hamayne via a Pd[0]-Catalyzed Intramolecular Alder-Ene Reaction
作者:Laurent Petit、Martin G. Banwell、Anthony C. Willis
DOI:10.1021/ol2023938
日期:2011.11.4
The racemic form of the title alkaloid, 1, has been prepared in 13 steps from the ring-fused gem-dibromocyclopropane 7. Key transformations include the thermally induced electrocyclic ring-opening of compound 7, the Pd[0]-catalyzed intramolecular Alder-ene (IMAE) reaction of the derived sulfonamide (±)-12, and the conversion of the ensuing C-3a-arylhexahydroindole (±)-16 into (±)-hamayne via a Pictet–Spengler
The 80% aqueous methanolic extract from the bulbs of Crinum yemense showed a potent inhibitory effect on nitric oxide production in lipopolysaccharide-activated macrophages. Three new crinine-type alkaloids, yemenines A (1), B (2), and C (3), were isolated from the herbal extract together with six known alkaloids. The absolute configurations of 1-3 were determined on the basis of chemical and physicochemical evidence. The effects of the isolated alkaloids on nitric oxide production in lipopolysaccharide-activated macrophages were examined, and several alkaloids, e.g. 1, (+)-bulbispermine (6), (+)-crinamine (7), (+)-6-hydroxycrinamine (8), and (-)-lycorine (9), showed inhibitory effects on nitric oxide production and induction of inducible nitric oxide synthase.
Application of Electrocyclic Ring-Opening and Desymmetrizing Nucleophilic Trappings of <i>meso</i>-6,6-Dibromobicyclo[3.1.0]hexanes to Total Syntheses of Crinine and Haemanthamine Alkaloids
作者:Ping Lan、Martin G. Banwell、Anthony C. Willis
DOI:10.1021/acs.joc.9b00018
日期:2019.3.15
radical cyclization, and Pictet–Spengler reactions, into (−)- or (+)-crinane (1 or ent-1, respectively). Variations on these protocols were applied to the totalsyntheses of (+)- and (−)-11-hydroxyvattitine [(+)- and (−)-3], (+)- and (−)-bulbispermine [(+)- and (−)-4], (+)- and (−)-haemanthamine [(+)- and (−)-5], (+)- and (−)-pretazettine [(+)- and (−)-6], and (+)- and (−)-tazettine [(+)- and (−)-7] as
The Structure of Hamayne, a New Alkaloid from<i>Crinum asiaticum</i>L.<i>var. japonicum</i>Baker
作者:Masamitsu Ochi、Hitoshi Otsuki、Kosho Nagao
DOI:10.1246/bcsj.49.3363
日期:1976.11
The structure of hamayne isolated from the fruit of Crinum asiaticum L. var. japonicum Baker was established to be O-demethylcrinamine (IV) on the basis of spectral and chemical evidence.
根据光谱和化学证据,从 Crinum asiaticum L. var. japonicum Baker 果实中分离出的 hamayne 的结构被确定为 O-demethylcrinamine (IV)。