The base-catalyzed cycloaddition and double Michael cyclization of substituted Nazarov reagents and of 1-phenylsulfinyl analogs, with 2-carbomethoxy-2-cyclohexen-1-one 1 yielding cis-decalins is reported. The reaction is highly stereoselective affording cis, cis-or cis, t rans-decalins. Mechanistic aspects are briefly discussed.
