Stereoselective radical cascade approach to benzo[alpha]quinolizidines

Authors
Ishibashi, H Inomata, M Ohba, M Ikeda, M
Citation
H. Ishibashi et al., Stereoselective radical cascade approach to benzo[alpha]quinolizidines, TETRAHEDR L, 40(6), 1999, pp. 1149-1152
Citations number
23
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
TETRAHEDRON LETTERS
ISSN journal
00404039 → ACNP
Volume
40
Issue
6
Year of publication
1999
Pages
1149 - 1152
Database
ISI
SICI code
0040-4039(19990205)40:6<1149:SRCATB>2.0.ZU;2-Z
Abstract
The treatment of enamide 15, having an (E)-4-ethoxycarbonyl-3-butenyl group on the nitrogen atom. with Bu3SnH-AIBN in boiling benzene, afforded a 1.2: 1 mixture of two benzo[a] quinolizidine stereoisomers 16 and 17 as a result of cascade radical cyclization. A similar treatment of the (2)-4-ethoxycar bonyl-3-butenyl congener 19 gave 16 and 17 in a ratio of 3.4:1. The high st ereoselectivity (16:17 = 37:1) from 19 was obtained using Et3B as the initi ator at -78 degrees C in toluene. (C) 1999 Elsevier Science Ltd. All rights reserved.