One-pot, four-different-component annulations: flexible and efficient conversion of n-sized cycloalkenones into n+4 alkenolides

Article abstract of DOI:10.1016/S0040-4039(00)95592-8

Five-, six-, and seven-membered conjugated cycloalkenones undergo one-pot conjugate addition with tri-n-butyltinlithium followed by 1,4-addition to vinyl ketones and then aldol addition to aldehydes leading to cyclic hemiketals 2. Lead tetraacetate oxidative fragmentation produces various 4-atom enlarged, vicinally disubstituted, regiospecifically and stereospecifically unsaturated macrolides 3.