N-monochlorination of N-unprotected α-amino esters and α-amino-β-diesters was efficiently and very simply effected by using inexpensive effervescent sodium dichloroisocyanurate tablets for water disinfection in a biphasic organic solvent-water system. Subsequent dehydrochlorination provided α,β-didehydroaminoacid esters, whose hydrogenation would allow the starting compounds to be easily racemized
Efficient Resolution of<i>cis</i>-(±)-Dimethyl 1-Acetylpiperidine-2,3-dicarboxylate with Soluble<i>Candida antarctica</i>Lipase B (CAL B)
作者:Perla Ramesh、Tirunagari Harini、Nitin W. Fadnavis
DOI:10.1021/op5003424
日期:2015.1.16
(2S,3R)-Dimethyl 1-acetylpiperidine-2,3-dicarboxylate, a valuable intermediate for moxifloxacin, was prepared by CAL B catalyzed kinetic resolution of the racemic diester. The reaction has an optimum temperature of 45–50 °C and an optimum pH of 7.5. It follows typical Michaelis–Menten kinetics with Vmax,obsd = 0.061 ± 0.008 M/h/g, Km,obsd = 0.2 ± 0.045 M at 45 °C. The reaction is highly enantioselective