Manipulation of substituents at nitrogen in tropanes, homotropanes, and dehydro- derivatives
摘要:
Trop-6-ene (8-methyl-8-azabicyclo[3.2.1]oct-6-ene) and substituted N-benzylnortrop-6-enes are synthesised. N-Debenzylation of tropanes fails using a wide variety of non-hydrogenolytic conditions despite effective application in model piperidine derivatives; debenzylation of homotropanes is more successful, giving norhomotropane and norhomotrop-7-ene. Bridged N-benzyl compounds react more slowly than N-methyl analogues with chloroformates; the resulting quaternary intermediates are more prone than the N-methyl analogues to suffer competitive reversion to the starting amine, especially in the tropanes, consistent with slower S(N)2 attack at the benzylic carbon during decomposition; the use of an N-p-methoxybenzyl group does allow partial debenzylation to nortrop-6-ene, suggesting greater SNI character in the decomposition step in this case. 'Equatorial' attack is preferred in methylation of N-benzyl-nortrop-6-ene and -homotrop-7-ene with CH3I; subsequent reductive debenzylation of the quaternary salt achieves overall replacement of N-benzyl by N-methyl in both cases. VT NMR studies show the presence of a single 'equatorial' invertomer (Cl syn- to the 2C-bridge) in N-chloro-norhomotropanes and -7-enes and, by analogy, in the N-alkyl compounds. (C) 1998 Elsevier Science Ltd. All rights reserved.
Willstaetter, Chemische Berichte, 1901, vol. 34, p. 134
作者:Willstaetter
DOI:——
日期:——
BILE ACID DERIVATIVES AS FXR/TGR5 AGONISTS AND METHODS OF USE THEREOF
申请人:ENANTA PHARMACEUTICALS, INC.
公开号:US20160289262A1
公开(公告)日:2016-10-06
The present invention provides compounds represented by Formula I, or pharmaceutically acceptable salts, stereoisomers, solvates, hydrates or combination thereof,
The invention also provides pharmaceutical compositions comprising these compounds and methods of using this compounds for treating FXR-mediated or TGR5-mediated diseases or conditions.
Manipulation of substituents at nitrogen in tropanes, homotropanes, and dehydro- derivatives
作者:Nicola M. Howarth、John R. Malpass、Craig R. Smith
DOI:10.1016/s0040-4020(98)00643-7
日期:1998.9
Trop-6-ene (8-methyl-8-azabicyclo[3.2.1]oct-6-ene) and substituted N-benzylnortrop-6-enes are synthesised. N-Debenzylation of tropanes fails using a wide variety of non-hydrogenolytic conditions despite effective application in model piperidine derivatives; debenzylation of homotropanes is more successful, giving norhomotropane and norhomotrop-7-ene. Bridged N-benzyl compounds react more slowly than N-methyl analogues with chloroformates; the resulting quaternary intermediates are more prone than the N-methyl analogues to suffer competitive reversion to the starting amine, especially in the tropanes, consistent with slower S(N)2 attack at the benzylic carbon during decomposition; the use of an N-p-methoxybenzyl group does allow partial debenzylation to nortrop-6-ene, suggesting greater SNI character in the decomposition step in this case. 'Equatorial' attack is preferred in methylation of N-benzyl-nortrop-6-ene and -homotrop-7-ene with CH3I; subsequent reductive debenzylation of the quaternary salt achieves overall replacement of N-benzyl by N-methyl in both cases. VT NMR studies show the presence of a single 'equatorial' invertomer (Cl syn- to the 2C-bridge) in N-chloro-norhomotropanes and -7-enes and, by analogy, in the N-alkyl compounds. (C) 1998 Elsevier Science Ltd. All rights reserved.