Palladium (II) catalyzed regioselective lactonization of steroids. Chemoselective construction of novel estrone derivatives

Authors
Troisi, L Vasapollo, G El Ali, B Mele, G Florio, S Capriati, V
Citation
L. Troisi et al., Palladium (II) catalyzed regioselective lactonization of steroids. Chemoselective construction of novel estrone derivatives, TETRAHEDR L, 40(9), 1999, pp. 1771-1774
Citations number
15
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
40
Issue
9
Year of publication
1999
Pages
1771 - 1774
Database
ISI
SICI code
0040-4039(19990226)40:9<1771:P(CRLO>2.0.ZU;2-H
Abstract
Palladium acetate and 1,4-bis(diphenylphosphino)butane (dppb) catalyze regi oselective cyclocarbonylation of 4-allylsteroids forming exclusively 7-memb ered ring lactones with excellent yields (96-98 %). The stereoselective add ition of an epoxide ring on the side-chain of steroids is realized by coupl ing the carbonyl group of the cyclopentanone ring of the steroid with 2-ben zothiazolylchloromethyllithium 1 or 4,4-dimethyl-2-oxazolinylchloroalkylith iums 2 and 3. (C) 1999 Published by Elsevier Science Ltd. All rights reserv ed.