The first asymmetric total synthesis of (−)-Linderol A, a potent inhibitor of melanin biosynthesis ofcultured B-16 melanoma cells, has been achieved via two key reactions: a diastereoselective [2+2]photocycloaddition of a coumarin-3-carboxylate bearing a chiral auxiliary with 3-methyl-1-butene and asubsequent stereoconvergent transformation of the photoadducts with use of dimethylsulfoxoniummethylide to afford a tetrahydrodibenzofuran derivative.
