title: Synthesis of chiral alpha-hydroxy amides by two sequential enzymatic catalyzed reactions.
abstract: Enantiomerically pure alpha-hydroxy amides have been prepared from the corresponding alpha-oxo esters by the use of a double sequence reaction involving in a first step the highly enantioselective Saccharomyces cerevisiae bioreduction and then in a second step, the resulting alpha-hydroxy esters followed a non-enantiospecific lipase catalyzed aminolysis with n-butylamine reaction. In the first non-organic solvent process, the moistened baker's yeast reduced seven alpha-oxo esters with high conversions degree (93% for one substrate and >99% for the others) and high enantioselectivities [>99% for all the substrates except for ketopantoyl lactone, which gave 88% of enantiomeric excess (ee)]. At the same way, the isolated resulting chiral alpha-hydroxy esters were subjected to the second Candida antarctica lipase fraction B (CAL-B) catalyzed aminolysis in dioxane conducting to the corresponding chiral alpha-hydroxy amides with high conversions degree, between 88 and 99%. Both processes were carried out at 28-30 degrees C.
authors.affiliation: UNIDA, Instituto Tecnológico de Veracruz, Av. Miguel A. de Quevedo # 2779, Veracruz, Veracruz, 91897, Mexico.
authors.forename: Yeritzia
authors.initials: Y
authors.lastname: Salinas
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Oliart
authors.forename: Mario
authors.initials: M
authors.lastname: Ramírez-Lepe
authors.forename: Arturo
authors.initials: A
authors.lastname: Navarro-Ocaña
authors.forename: Gerardo
authors.initials: G
authors.lastname: Valerio-Alfaro
mesh_terms: D000577:Amides / Q000737:chemistry / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D002384:Catalysis; D004146:Dioxanes; D004952:Esters / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins; D008049:Lipase / Q000378:metabolism*; D010084:Oxidation-Reduction; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D000577:Amides; D004146:Dioxanes; D004952:Esters; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D008049:Lipase; C431349:lipase B, Candida antarctica