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.
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.
Hydrolase-Catalysed Preparation of Chiral α,α-Disubstituted Cyanohydrin Acetates
作者:Jarle Holt、Isabel W. C. E. Arends、Adriaan J. Minnaard、Ulf Hanefeld
DOI:10.1002/adsc.200700053
日期:2007.6.4
The enzymatichydrolysis of esters of tertiary alcohols has long been a challenge. In particular their kinetic resolutions have virtually not been addressed. Here we describe the successful kinetic resolution of α,α-disubstituted cyanohydrin acetates, a type of protected tertiary alcohols that form particularly interesting building blocks in organic synthesis. Utilising Subtilisin A the hydrolysis reaction