Dedicated to Professor Helmut Vorbrüggen on the occasion of his 90th birthday
Abstract
The samarium diiodide promoted reductive cyclization of a series of γ-aryl ketones
with acetoxy, alkoxy, and siloxy groups in ortho-, meta-, and para-positions was investigated. Only precursors with p-acetoxy, p-tert-butoxy, or p-siloxy substituents furnished decent yields of the desired 7-oxy-1,2,3,4,6,8a-hexahydronaphthalene
derivatives. The products were formed without contamination with the regioisomeric
bicyclic products containing conjugated double bonds. Typical reactions exploiting
the silyl enol ether moiety of the 7-(tert-butyldimethylsiloxy)-1,2,3,4,6,8a-hexahydronaphthalene derivative were performed,
allowing stereoselective access to highly substituted hexahydro-, octahydro-, or
decahydronaphthalene derivatives.
Key words
dearomatization - ketyl - hexahydronaphthalene - radical - samarium diiodide - silyl
enol ether