Syntheses of optically active γ-ketothiols and the esters by lipase-catalyzed hydrolysis via α-acetylthiomethylation of ketones
摘要:
The alpha-acetylthiomethylation of ketones was achieved by the reaction of ketones or the enamines with N,N-bis-(acetylthiomethyl)-p-chloroaniline in the presence of trifluoroacetic acid. The resulting thiolesters were hydrolyzed enantioselectively by catalysis of lipases. (C) 1997 Elsevier Science Ltd.
Nucleophilic Reaction upon Electron-Deficient Pyridone Derivatives. XIII. Regioselective Synthesis of 2-Substituted 3-Nitropyridines by One-Pot Reaction of Either 4- or 6-Substituted 1-Methyl-3,5-dinitro-2-pyridones with Ketones and Ammonia
A one-pot synthesis of 2-substituted 3-nitropyridines was developed by a ring transformation of 6- or 4-substituted 1-methyl-3,5-dinitro-2-pyridones (2 or 3) with ammonia and enamines derived from ketones. Some intermediates having a 2,6-diazabicyclo[3.3.1]nonane skeleton were isolated from reactions of 3. The ring transformation proceeds via an addition-addition-elimination-elimination mechanism.