Efficient Epoxide Hydrolase Catalyzed Resolutions of (+)- and (-)-cis/trans-Limonene Oxides

The synthesis of enantiomerically pure cis- and trans-limonene oxides and their corresponding diols from easily accessible raw materials has been of much interest for a long time. A straightforward one-step biocatalytic resolution of the (+)-cis/trans limonene oxide and the (-)-cis/trans-limonene oxide has been investigated. Epoxide hydrolases showing complementary stereoselectivity were recombinantly expressed in Escherichiacoli, which allowed easy purification. The conditions for the selective epoxide hydrolase catalyzed ring-opening reactions have been optimized and enabled the preparation of all limonene oxide enantiomers. The described utilization of recombinant epoxide hydrolases for the synthesis of all limonene oxide enantiomers was superior to chemical routes and represents a highly resource-efficient one-step preparation.