Tandem Michael/Michael reactions mediated by phosphines or aryl thiolates

Tri-n-butyl phosphine was found to effect tandem Michael/Michael cyclisations leading to the formation of cyclopentenes and cyclohexenes in good yields, whilst p-TolSH in conjunction with a catalytic amount of p-TolSNa effected cyclisation to the corresponding cyclopentanes and cyclohexanes. (c) 2006 Published by Elsevier Ltd.