Stereocontrolled synthesis of functionalised cyclohexanes via the lithium amide-mediated rearrangement of a meso 4,5-disubstituted cyclohexene oxide

Reaction of a 90:10 mixture of diastereomeric meso 4,5-disubstituted cyclohexene oxides (prepared via a stereoselective epoxidation reaction) with a mixed base system of a lithium amide and potassium tert-butoxide produces a 72% yield of an allylic alcohol and a 9.6% yield of recovered epoxide, both as single diastereoisomers. The relative stereochemistry of the epoxides and the allylic alcohol is established by converting the allylic alcohol into a novel bicyclic ether. The allylic alcohol is also used to prepare single diastereosiomers of a range of functionalised cyclohexanes. (C) 1997 Elsevier Science Ltd.