Enantioselective lipase-catalysed kinetic resolution of acyloxymethyl and ethoxycarbonylmethyl esters of 1,4-dihydroisonicotinic acid derivatives
作者:Arkadij Sobolev、Maurice C.R. Franssen、Janis Poikans、Gunars Duburs、Aede de Groot
DOI:10.1016/s0957-4166(02)00655-9
日期:2002.10
The lipase-catalysed kinetic resolution of four derivatives of 4-[(acyloxy)methyl] and 4-ethoxycarbonylmethyl 3-methyl 5-propyl 2,6-dimethyl-1,4-dihydro-3,4,5-pyridinetricarboxylates has been investigated. Whereas the enantioselectivity of lipases towards the acyloxymethyl derivatives was rather low, the Candida antarctica lipase B (Novozym 435(R), CAL-B)-catalysed hydrolysis of the ethoxycarbonylmethyl ester of 1,4-dihydroisonicotinic acid was enantioselective. In water-saturated diisopropyl ether at 45degreesC the enantioselectivity of CAL-B toward the ethoxycarbonylmethyl ester was rather moderate (E = 13.8), but it was enhanced at rt and +4degreesC (E = 21.5 and E = 28.9, respectively). A high enantiomeric ratio (E = 45.3) was reached at subzero temperatures, although at the expense of the reaction rate. (C) 2002 Elsevier Science Ltd. All rights reserved.
The derivatives of 2,6-dimethyl-1,4-dihydroisonicotinic acid and their antiplatelet properties
resonance and supported by quantum chemical calculations. The dihydropyridine ring in each of the compounds exists in flattened boat-type conformation. The observed ring distortions around the C(4) and N(1) atoms are interrelated. The substituent at N(1) has great influence on nitrogen atom pyramidality. The 1H, 13C and 15NNMRchemicalshifts and couplingconstants are discussed in terms of their relationship