Asymmetric synthesis of benzoquinolizidines: a formal synthesis of (-)-emetine
摘要:
Chiral formamidines affixed to tetrahydroisoquinoline derivatives affords the appropriate precursor 9 to various benzo[a]quinolizidines 2 and 3 and dibenzo[a,g]quinolizidines 4 in modest to high optical purity. Both 3 and 4 have been utilized in total syntheses of natural emetine 1, thus the route herein constitutes a formal total synthesis of 1. Furthermore, Mannich cyclizations of 1-alkylisoquinolines 18a-c proceeded with or without loss of absolute stereochemistry at the C-1 position. Explanation for this behavior is based upon whether a [3,3] rearrangement or a Mannich reaction takes place. The former results in virtually complete racemization of 18, whereas the latter totally conserves the chirality in 18. Finally, 1-alkynylisoquinolines of high optical purity were transformed, via the Overman protocol, to alkylidine benzo[a]quinolizidines 24 in good yield and to our knowledge, high enantiomeric excess.
The present invention relates to compounds of formula (I)
1
wherein R
1
is as defined in the description, and pharmaceutically acceptable salts thereof. The compounds are useful for the treatment and/or prophylaxis of diseases which are associated with DPP-IV, such as diabetes, particularly non-insulin dependent diabetes mellitus, and impaired glucose tolerance.
RUBIRALTA, MARIO;DIEZ, ANNA;BALET, ANTONIA;BOSCH, JOAN, TETRAHEDRON, 43,(1987) N 13, 3021-3030
作者:RUBIRALTA, MARIO、DIEZ, ANNA、BALET, ANTONIA、BOSCH, JOAN
DOI:——
日期:——
HEXAHYDROPYRIDOISOQINOLINES AS DPP-IV INHIBITORS
申请人:F.HOFFMANN-LA ROCHE AG
公开号:EP1638968B1
公开(公告)日:2009-07-29
US7718666B2
申请人:——
公开号:US7718666B2
公开(公告)日:2010-05-18
Asymmetric synthesis of benzoquinolizidines: a formal synthesis of (-)-emetine
作者:Joseph W. Guiles、A. I. Meyers
DOI:10.1021/jo00024a032
日期:1991.11
Chiral formamidines affixed to tetrahydroisoquinoline derivatives affords the appropriate precursor 9 to various benzo[a]quinolizidines 2 and 3 and dibenzo[a,g]quinolizidines 4 in modest to high optical purity. Both 3 and 4 have been utilized in total syntheses of natural emetine 1, thus the route herein constitutes a formal total synthesis of 1. Furthermore, Mannich cyclizations of 1-alkylisoquinolines 18a-c proceeded with or without loss of absolute stereochemistry at the C-1 position. Explanation for this behavior is based upon whether a [3,3] rearrangement or a Mannich reaction takes place. The former results in virtually complete racemization of 18, whereas the latter totally conserves the chirality in 18. Finally, 1-alkynylisoquinolines of high optical purity were transformed, via the Overman protocol, to alkylidine benzo[a]quinolizidines 24 in good yield and to our knowledge, high enantiomeric excess.