Stannylation and germylation of some 4-, 5- and 6-Alkylcyclohex-2-enyl chlorides

Abstract

The allylic alcohols, trans-5-t-butylcyclohex-2-enol, trans-4-t-butylcyclohex-2-enol and trans-4- methylcyclohex-2-enol, have been converted into cyclohex-2-enyl chlorides by reaction with thionyl chloride and N-chlorosuccinimide-dimethyl sulfide. The stereochemistry of the allylic chlorides has been determined by ¹H and ¹³C nuclear magnetic resonance spectroscopy. Stannylation of these chlorides with trimethyltinlithium, and triphenyltinlithium, has been examined and the resulting stannanes fully characterized by ¹H, ¹³C and ¹¹⁹Sn n.m.r, spectroscopy, and electrophilic cleavage (acidolysis with deuterated trifluoroacetic acid) to the corresponding deuterocyclohexenes. A less extensive study of germylation (trimethylgermyllithium in hexamethylphosphoramide) was conducted also, and the allylic germanes fully characterized. Triphenyltinlithium and trimethylgermyllithium exhibit higher levels of stereo- and regio-specificity in chloride displacement than trimethyltinlithium.