Efficient Enantioselective Syntheses of (+)-Dalesconol A and B

We
herein report the first enantioselective syntheses of immunosuppressants
(+)-dalesconol A and B in a highly efficient and concise manner, which
features an efficient palladium-catalyzed enantioselective dearomative
cyclization–kinetic resolution cascade to install the chiral
all-carbon quaternary center, an effective sterically hindered Stille
coupling, a powerful 2,3-dichloro-5,6-dicyano-1,4-benzo­quinone
(DDQ) oxidation to furnish all requisite unsaturation, and a tandem
hydrolysis–ring closure sequence.