Stereoselective reduction of .gamma.-oxobutanoic acids using DIBAL-H and zinc chloride
摘要:
A variety of gamma-aromatic gamma-ketobutanoic acids can be reduced selectively, under optimized conditions, by the use of DIBAL-H and ZnCl2 to provide the (RS,SR)-gamma-aryl-gamma-hydroxy-beta-methylbutanoic acids. Further evidence has been gathered to support the hypothesis that the reaction proceeds by formation of a seven-membered ring complex with the aluminium or zinc atom bridging the ketone and carboxyl groups which preceeds the reduction step and that this templated reduction accounts for observed high diastereoselectivity. Also we have shown that some gamma-aryl-gamma-butyrolactones can be easily transformed via an oxidative cleavage of the aromatic ring to provide selective synthesis of either cis- or trans-tetrahydro-3-methyl-5-oxo-2-furancarboxylic acid derivatives.
Synthesis and structure–activity relationships of 2-acylamino-4,6-diphenylpyridine derivatives as novel antagonists of GPR54
摘要:
GPR54 is a G protein-coupled receptor (GPCR) which was formerly an orphan receptor. Recent functional study of GPR54 revealed that the receptor has an essential role to modulate sex-hormones including GnRH. Though antagonists of GPR54 are expected to be novel drugs for sex-hormone dependent diseases such as prostate cancer or endometriosis, small molecule GPR54 antagonists have not been reported. We have synthesized a series of 2-acylamino-4,6-diphenylpyridines to identify potent GPR54 antagonists. Detailed structure-activity relationship studies led to compound 9l with an IC50 value of 3.7 nM in a GPR54 binding assay, and apparent antagonistic activity in a cellular functional assay. (C) 2010 Elsevier Ltd. All rights reserved.
The present invention provides a compound which has metastin receptor antagonist activity and is useful for preventing and treating hormone-dependent cancer, benign prostatomegaly, endometriosis, precocious puberty, uterine myoma or the like. More specifically, the present invention provides a compound, represented by the formula:
or a salt thereof, a prodrug thereof, and a pharmaceutical agent containing the same; wherein Ring A represents a 5- to 8-membered homocyclic or heterocyclic group optionally having a substituent other than formula —X-R
1
wherein X represents a bond or a spacer, and R
1
represents optionally substituted amino or an optionally substituted nitrogen-containing heterocyclic group; Ring B represents an optionally substituted benzene ring; R
2
represents an optionally substituted homocyclic or heterocyclic group; and R
3
and R
4
independently represent a hydrogen atom, cyano, acyl or an optionally substituted hydrocarbon group.
GPR54 is a G protein-coupled receptor (GPCR) which was formerly an orphan receptor. Recent functional study of GPR54 revealed that the receptor has an essential role to modulate sex-hormones including GnRH. Though antagonists of GPR54 are expected to be novel drugs for sex-hormone dependent diseases such as prostate cancer or endometriosis, small molecule GPR54 antagonists have not been reported. We have synthesized a series of 2-acylamino-4,6-diphenylpyridines to identify potent GPR54 antagonists. Detailed structure-activity relationship studies led to compound 9l with an IC50 value of 3.7 nM in a GPR54 binding assay, and apparent antagonistic activity in a cellular functional assay. (C) 2010 Elsevier Ltd. All rights reserved.
Stereoselective reduction of .gamma.-oxobutanoic acids using DIBAL-H and zinc chloride
作者:R. Frenette、M. Monette、M. A. Bernstein、R. N. Young、T. R. Verhoeven
DOI:10.1021/jo00009a030
日期:1991.4
A variety of gamma-aromatic gamma-ketobutanoic acids can be reduced selectively, under optimized conditions, by the use of DIBAL-H and ZnCl2 to provide the (RS,SR)-gamma-aryl-gamma-hydroxy-beta-methylbutanoic acids. Further evidence has been gathered to support the hypothesis that the reaction proceeds by formation of a seven-membered ring complex with the aluminium or zinc atom bridging the ketone and carboxyl groups which preceeds the reduction step and that this templated reduction accounts for observed high diastereoselectivity. Also we have shown that some gamma-aryl-gamma-butyrolactones can be easily transformed via an oxidative cleavage of the aromatic ring to provide selective synthesis of either cis- or trans-tetrahydro-3-methyl-5-oxo-2-furancarboxylic acid derivatives.