A novel method for the introduction of a 5 beta-methyl group into 4,5 alpha-epoxymorphinan-6-ones via the enol ether

Authors
Krassnig, R Schmidhammer, H Wurst, K
Citation
R. Krassnig et al., A novel method for the introduction of a 5 beta-methyl group into 4,5 alpha-epoxymorphinan-6-ones via the enol ether, HELV CHIM A, 83(2), 2000, pp. 380-383
Citations number
9
Categorie Soggetti
Chemistry & Analysis",Chemistry
Journal title
HELVETICA CHIMICA ACTA
ISSN journal
0018019X → ACNP
Volume
83
Issue
2
Year of publication
2000
Pages
380 - 383
Database
ISI
SICI code
0018-019X(2000)83:2<380:ANMFTI>2.0.ZU;2-P
Abstract
The introduction of a 5 beta-methyl group into 14-alkoxy substituted naltre xone derivatives was accomplished via the enol ethers 2a and 2b by means of the 'LICKOR' (t-BuLi/t-BuOK) base system. According to this new method. th e highly selective delta-opioid antagonist HS 378 (7b) and its 14-methoxy a nalog 7a, both originally prepared in nine steps from thebaine, are now ava ilable in only four steps.