Compound 8a

(2S*,4'aR*,9'aR*)-4’a,6,7’-trimethoxy-3',4',5',6',7,8-hexamethyl-2',3,4,4'a,9',9'a- hexahydrospiro(1-benzopyran-2,1'-xanthen)-2'-one

From: Chemoselective oxidative generation of ortho-quinone methides and tandem transformations