Synthesis of chiral α-hydroxy amides by two sequential enzymatic catalyzed reactions

• Published in: Applied microbiology and biotechnology 2007-05, Vol.75 (2), p.297-302
• Main Authors: Salinas, Yeritzia, Oliart, Rosa María, Ramírez-Lepe, Mario, Navarro-Ocaña, Arturo, Valerio-Alfaro, Gerardo
• Format: Article
• Language: English
• Subjects: Amides - chemistry; Amides - metabolism; Biological and medical sciences; Bioreduction; Biotechnology; Biotechnology - methods; CAL-B; Candida antarctica; Catalysis; Chiral; Dioxanes; Esters - chemistry; Esters - metabolism; Fundamental and applied biological sciences. Psychology; Fungal Proteins; Lipase - metabolism; Oxidation-Reduction; Saccharomyces cerevisiae; Saccharomyces cerevisiae - enzymology; Saccharomyces cerevisiae Proteins - metabolism; α-Hydroxy amides; α-Hydroxy esters; α-oxo esters
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/s00253-006-0829-0

Enantiomerically pure α-hydroxy amides have been prepared from the corresponding α-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 α-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 α-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 α-hydroxy esters were subjected to the second Candida antarctica lipase fraction B (CAL-B) catalyzed aminolysis in dioxane conducting to the corresponding chiral α-hydroxy amides with high conversions degree, between 88 and 99%. Both processes were carried out at 28-30°C.