Synthesis of chiral epihalohydrins using haloalcohol dehalogenase A from Arthrobacter erithii H10a

Investigation of the epoxide enantiomers formed by the action of the haloalcohol dehalogenase from Arthrobacter erithii H10a revealed that (R)-epichlorohydrin (ECH) was selectively produced from 1,3-dichloro-2-propanol (1,3-DCP). A maximum enantiomeric excess (e.e. > 95%) of (RI-ECH was obtained when dehalogenation of 1,3-DCP occurred in rile presence of an excess of KBr. During the reverse reaction, (R)-ECH was stereoselectively halogenated to form 1,3-DCP of the halogen in the reaction mixture was chloride; however, if chloride was substituted by bromide, the (s)-isomer was halogenated preferentially resulting in the accumulation of the (R)-isomer. (R)-epibromohydrin (EBH) was formed as the result of transhalogenation. If the starting substrates were EBH and KCl, the (R)-isomer was selectively chlorinated while the transhalogenation product was (s)-ECH. (C) 1998 Elsevier Science Inc.