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

摘要

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-l,4-benzoquinone (DDQ) oxidation to furnish all requisite unsaturation, and a tandem hydrolysis-ring closure sequence.