trans-Cycloalkenes. Part 13. 1-Methylthiomethoxy-trans-cyclo-octene and 1-methoxy-trans-cyclo-octene by Peterson elimination

Abstract

Methods are described, based on model experiments with cyclohexyl analogues, for the preparation of c-2-methylthiomethoxy-t-2-trimethylsilylcyclo-octan-r-1-ol (21) and c-2-methoxy-t-2-trimethylsilyl-cyclo-octan-r-1-ol (22). These underwent a stereospecific elimination on treatment with KH–Me₂SO to give respectively 1-methylthiomethoxy-trans-cyclo-octene (23) and 1-methoxy-trans-cyclo-octene (25) as transient compounds which fairly rapidly isomerised to their cis-isomers.