Lipase catalyzed resolution of the quaternary stereogenic center in ketone-derived benzo-fused cyclic cyanohydrins
摘要:
The enantioselective preparation of both enantiomers of the benzo-fused cyanohydrin derived from alpha-tetralone via lipase catalyzed processes is described. The (S)-enantiomer has been obtained as the remaining substrate in the CAL-A catalyzed aminolysis of the methoxyacetylated derivative, using a structurally related amine as the nucleophile. The (R)-enantiomer has been obtained as the product of CAL-A or PSL-C catalyzed hydrolysis of the methoxyacetylated derivative in organic solvents. The resolutions of several structural analogs of this cyanohydrin have been also tested under similar conditions. (C) 2011 Elsevier Ltd. All rights reserved.
13C NMR as a general tool for the assignment of absolute configuration
作者:Iria Louzao、José Manuel Seco、Emilio Quiñoá、Ricardo Riguera
DOI:10.1039/c0cc02774j
日期:——
(13)C NMR, alone or in combination with (1)H NMR, allows the assignment of the absolute configuration of chiral alcohols, amines, carboxylic acids, thiols, cyanohydrins, sec,sec-diols and sec,sec-aminoalcohols, derivatized with appropriate chiral auxiliaries. This extends the assignment possibilities of NMR to fully deuterated and to nonproton containing compounds.
Lipase catalyzed resolution of the quaternary stereogenic center in ketone-derived benzo-fused cyclic cyanohydrins
作者:Jesús A. Rodríguez-Rodríguez、Vicente Gotor、Rosario Brieva
DOI:10.1016/j.tetasy.2011.07.004
日期:2011.6
The enantioselective preparation of both enantiomers of the benzo-fused cyanohydrin derived from alpha-tetralone via lipase catalyzed processes is described. The (S)-enantiomer has been obtained as the remaining substrate in the CAL-A catalyzed aminolysis of the methoxyacetylated derivative, using a structurally related amine as the nucleophile. The (R)-enantiomer has been obtained as the product of CAL-A or PSL-C catalyzed hydrolysis of the methoxyacetylated derivative in organic solvents. The resolutions of several structural analogs of this cyanohydrin have been also tested under similar conditions. (C) 2011 Elsevier Ltd. All rights reserved.
The Use of a Single Derivative in the Configurational Assignment of Ketone Cyanohydrins
作者:Iria Louzao、José M. Seco、Emilio Quiñoá、Ricardo Riguera
DOI:10.1002/ejoc.201001107
日期:2010.12
The absolute stereochemistry of ketone cyanohydrins can be easily determined by preparing a single MPA derivative. The comparison of two NMR spectra at different temperatures allows the assignment by just paying attention to the evolution of the cyanohydrin chemical shifts. The special case of α-aryl-substituted cyanohydrins is also described.