SHORT SYNTHESIS OF (+ -)-HIRSUTINE - DIRECT ADDITION OF DIMETHYL MALONATE ANION TO A 1,4-CONJUGATE IMINIUM SALT OF APPROPRIATE 3-ETHYLINDOLO[2,3-A]QUINOLIZIDINE/

Authors
LOUNASMAA M MIETTINEN J HANHINEN P JOKELA R
Citation
M. Lounasmaa et al., SHORT SYNTHESIS OF (+ -)-HIRSUTINE - DIRECT ADDITION OF DIMETHYL MALONATE ANION TO A 1,4-CONJUGATE IMINIUM SALT OF APPROPRIATE 3-ETHYLINDOLO[2,3-A]QUINOLIZIDINE/, Tetrahedron letters, 38(8), 1997, pp. 1455-1458
Citations number
15
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron letters → ACNP
ISSN journal
00404039
Volume
38
Issue
8
Year of publication
1997
Pages
1455 - 1458
Database
ISI
SICI code
0040-4039(1997)38:8<1455:SSO(-->2.0.ZU;2-N
Abstract
Direct addition of dimethyl malonate anion to a 1,4-conjugate iminium salt of 3-ethylindolo[2,3-a]quinolizidine 4a (regenerated from the cor responding alpha-aminonitrile 4b) afforded enamine 5. Catalytic hydrog enation of compound 5, led stereoselectively to compound 6 (pseudo), w hich is the highly desired intermediate for the preparation of several Corynanthe alkaloids, including (+/-)-hirsutine 7. (C) 1997 Elsevier Science Ltd.