Enantio- and diastereoselective synthesis of tetrahydrofuro[2,3-b]furan-2(3H)-one derivatives and related oxygen heterocycles via an asymmetric organocatalytic cascade process

Tetrahydrofuro[2,3-b]furan-2(3H)-one derivatives bearing four stereogenic centers were achieved via an asymmetric organocatalytic cascade process with excellent stereoselectivity in one single operation and H2O as the only side product. The alpha,beta-unsaturated carboxylic acid plays two important roles in the cascade process: the Michael acceptor and acidic co-catalyst for enamine catalysis.