Synthesis of Methyl-substituted 1-Cyclopentene-1-carboxylates and Related Compounds
作者:Akira Takeda、K\={o}ichi Shinhama、Sadao Tsuboi
DOI:10.1246/bcsj.50.1831
日期:1977.7
The treatment of methyl-substituted 1-chloro-2-oxo-1-cyclohexanecarboxylic esters (7a–e) with anhydrous Na2CO3 in refluxing xylene gave the corresponding methyl-substituted 1-cyclopentene-1-carboxylic esters (1a–e). Several intermediates important in the synthesis of natural products, such as 4,4-dimethyl-1-cyclopentene-1-carbaldehyde (9), 5-methyl-1-cyclopentene-1-carbaldehyde (12), α-(3-methyl-1
(−)-Isoiridomyrmecin was synthesized stereoselectively in 6 steps starting from 1-hydroxymethyl-5-methylcyclopentene and utilizing tlle asymmetric aza-Claisenrearrangement as a key step.
Process for isolating the antiviral agent [1S-(1alpha, 3alpha, 4beta)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one
申请人:Bristol-Myers Squibb Company
公开号:EP2433941A1
公开(公告)日:2012-03-28
The invention refers to a method for isolating entecavir or an entecavir intermediate from a diluted mixture, the diluted mixture comprising entecavir and water or a mixture comprising an entecavir intermediate and other process reagents comprising:
(a) adsorbing the diluted mixture onto a hydrophobic resin bed;
(b) washing the resin bed with water to remove salt; and
(c) eluting the entecavir or entecavir intermediate from the resin bed with an organic solvent.