SYNTHESIS OF CHIRAL EPIHALOHYDRINS USING HALOALCOHOL DEHALOGENASE-A FROM ARTHROBACTER-ERITHII H10A

Investigation of the epoxide enantiomers formed by the action of the h aloalcohol 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 prese nce of an excess of KBr. During the reverse reaction, (R)-ECH was ster eoselectively halogenated to form 1,3-DCP of the halogen in the reacti on mixture was chloride; however, if chloride was substituted by bromi de, the (s)-isomer was halogenated preferentially resulting in the acc umulation of the (R)-isomer. (R)-epibromohydrin (EBH) was formed as th e result of transhalogenation. If the starting substrates were EBH and KCl, the (R)-isomer was selectively chlorinated while the transhaloge nation product was (s)-ECH. (C) 1998 Elsevier Science Inc.