Regiospecific substitution of the carbon–boron bond of tris(4-methylfuran-3-yl)boroxine: a model ring C→BC→ABC approach towards eudesmanolides

A synthetic study of eudesmanolides was performed utilizing a Suzuki coupling reaction of tris(4-methylfuran-3-yl)boroxine (6) as the pivotal step. The other key reactions involved Friedel–Crafts acylation, Wacker–Tsuji reaction and aldol condensation. In this Ring C→BC→ABC approach, a model compound 3 towards the synthesis of eudesmanolides 11,13-dihydrotubiferin (1) and artogallin (2) was realized. In another model study, the five-membered analog 4 was also obtained.