1001879-50-0Relevant academic research and scientific papers
Stereoselective reduction of 2-hydroxy ketones towards syn- and anti-1,2-diols
Husain, Syed Masood,Stillger, Thomas,Duenkelmann, Pascal,Loedige, Melanie,Walter, Lydia,Breitling, Elke,Pohl, Martina,Buerchner, Mara,Krossing, Ingo,Mueller, Michael,Romano, Diego,Molinari, Francesco
scheme or table, p. 2359 - 2362 (2011/10/19)
Stereoselective reduction of 2-hydroxy ketones should in principle give access to syn- and anti-1,2-diols. anti-1,2-Diols are accessible in a highly selective way using zinc borohydride [Zn(BH4)2] under chelation control (dr>20:1). Diastereoselective reduction of unprotected or even protected 2-hydroxy ketones towards syn-1,2-diols could be achieved only with moderate selectivity of dr≤5:1. Even when using sterically demanding protecting groups and/or polymer-supported borohydride reagents high selectivity could not be achieved. A new ionic liquid-dependent borohydride reduction method, although highly attractive with respect to reaction engineering, resulted in only moderate to good selectivity. An efficient two-step biocatalytic method for the synthesis of syn-1,2-diols is described. The method relies on the whole-cell Pichia glucozyma-catalyzed stereoselective reduction of the unprotected (R)-2-hydroxy ketones (dr>10:1). The latter are accessible through thiamine diphosphate-dependent enzyme-catalyzed synthesis starting from simple aldehydes. Thus, biocatalytic transformations enable a process which is hardly accessible through present non-enzymatic methods. Copyright
Kinetic resolution of 1,2-diols through highly site- and enantioselective catalytic silylation
Zhao, Yu,Mitra, Aurpon W.,Hoveyda, Amir H.,Snapper, Marc L.
, p. 8471 - 8474 (2008/09/18)
(Chemical Equation Presented) Resolved to silylate: A chiral silylation catalyst is used for kinetic resolution of three classes of acyclic 1,2-diols. The catalyst differentiates, with excellent precision, between the two hydroxy groups of a substrate. The majority of the diols, obtained in high enantiomeric purity, cannot be accessed with similar stereochemical purity through catalytic asymmetric dihydroxylation.
