Synthesis of vulpinic and pulvinic acids from tetronic acid
作者:Yann Bourdreux、Ewen Bodio、Catherine Willis、Célia Billaud、Thierry Le Gall、Charles Mioskowski
DOI:10.1016/j.tet.2008.06.058
日期:2008.9
A common precursor, tetronic acid, was used in the synthesis of several vulpinic acids and pulvinicacids, which are pigments found in several lichens and mushrooms. The key features of this method are a two-step alkylidenation of benzyl tetronate and a Suzuki–Miyaura cross-coupling. The synthesis of several natural products, vulpinic acid, pinastricacid, xerocomic acid is described.
Six pulvinic acids (pulvinic, pinastric, atromentic, xerocomic, isoxerocomic, variegatic) and a polyporic acid (atromentin) were synthesised. A set of terphenyl-quinones was prepared through sequential Suzuki-Miyaura couplings. Then, a rearrangement into pulvinic bis-lactones was induced by the action of Ac2O/DMSO. Ringopenings and deprotections achieved total syntheses. Fluorescence properties of