Enzyme catalyzed addition of hydrocyanic acid to substituted pivalaldehydes—a novel synthesis of (R)-pantolactone

F Effenberger, J Eichhorn, J Roos

Index: Effenberger, Franz; Eichhorn, Joachim; Roos, Juergen Tetrahedron: Asymmetry, 1995 , vol. 6, # 1 p. 271 - 282

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Citation Number: 59

Abstract

(R)-Cyanohydrins (R)-2b-h are obtained in good optical yields by (R)-oxynitrilase catalyzed enantioselective addition of HCN to β-substituted pivalaldehydes 1b-h. Under optimized reaction conditions with highly purified (R)-oxynitrilase, hydroxypivalaldehyde (1a) is converted to (R)-2a in satisfactory chemical and optical yields. By acid-catalyzed hydrolysis the cyanohydrins (R)-2a-h cyclize directly to give crude (R)-pantolactone (R)-3 with ee- ...