Total Synthesis of Incarviditone and Incarvilleatone

The total synthesis of the racemic natural products (+/-)-incarviditone and (+/-)-incarvilleatone has been accomplished in three steps via biomimetic dimerization of (+/-)-rengyolone. Homochiral dimerization of (+/-)-rengyolone affords (+/-)-incarviditone through a domino oxa-Michael/Michael sequence. Heterochiral dimerization, involving a domino oxa-Michael/Michael/aldol reaction sequence, affords (+/-)-incarvilleatone. Single-crystal X-ray analysis of a derivative of (+/-)-incarviditone has resulted in revision of the originally proposed structure.