Microbial Desaturation of Bis(1-chloro-2-propyl) Ether into a Dichloro Vinyl Ether

摘要

Bis(chloropropyl)ethers are undesirable by-products of the industrial production of propylenoxide and epichlorohydrine by the two-step chlorohydrine process. Such by-products have been released into the environment.[1] They are considered an important class of environmental pollutants due to their persistence and toxicity. Compounds containing an ether bond are poorly biodegradable because the ether bridge is very stable.[2] In addition, metabolites resulting from ether transformation may be toxic for organisms or the organisms may lack the necessary enzymes for further degradation.[3] The aerobic biodegradation of bis(1-chloro-2-propyl)ether (1, DDE) by the Rhodococcus species strain DTB occurs by scission of the ether bridge resulting in the formation of chloroacetone (4), 1-chloropropan-2-ol (5) and the transient formation of a so far unknown metabolite.[4] The possible involvement of a flavin-containing monooxygenase and the formation of chloroacetone and 1-chloropropan-2-ol may indicate that scission of the ether bond is initiated by hydroxylation of DDE at C-2, which results in a hemiketal structure 3 that is unstable in aqueous solution and predisposed to spontaneous scission.