A Protecting‐Group‐Free Synthesis of (−)‐Salvinorin A
作者:Patrick Zimdars、Yuzhou Wang、Peter Metz
DOI:10.1002/chem.202100560
日期:2021.5.20
intramolecular Diels-Alder reactions were applied to generate the tricyclic core. A chemoselective Mitsunobu inversion of a syn 1,2-diol allowed for further streamlining of the original reaction sequence by two steps. Overall, (−)-salvinorin A was synthesized in only 16 steps starting from 3-furaldehyde with 1.4 % total yield. Furthermore, an alternative intramolecular Diels-Alder strategy employing a 2-bromo-1
Ring-Closing of 1,7- and 1,8-Enynes of Propargylic O,O-Acetals by Ruthenium-Catalysed Intramolecular Metathesis
作者:Don Antoine Lanfranchi、Christophe Bour、Bastien Boff、Gilles Hanquet
DOI:10.1002/ejoc.201000305
日期:2010.9
Acyclic 1,7- and 1,8-enynes with the alkyne moiety directly connected to the asymmetric carbon of an ethyl acetal have been obtained in two steps from the corresponding aldehydes. Ring-closing metathesis of these enynes delivered the corresponding six- and seven-membered cyclic 1,3-dienes in moderate-to-excellent yields. A competitive ethylene insertion into the alkyne moiety leading to trienes was observed