Total synthesis of (±)-methyl rishirilide B

[GRAPHICS] A regio and stereospecific total synthesis of (+/-)-methyl rishirilide B (2b), an (alpha)(2)-macroglobulin inhibitor, is described. A key feature of the synthetic plan was regiospecific construction of a hydroanthracenone intermediate through condensation of a phenylsulfonyl isobenzofuranone with a functionalized 2-cyclohexen-1-one. Introduction of the vicinal trans-hydroxyl groups in the densely functionalized A-ring was accomplished via a novel one-pot procedure that involved oxidation of enolate anions with the Davis reagent.