Organocatalytic Asymmetric Domino Knoevenagel/Diels–Alder Reactions: A Bioorganic Approach to the Diastereospecific and Enantioselective Construction of Highly Substituted Spiro[5,5]undecane‐1,5,9‐triones

A practical and environmentally friendly organocatalytic process for the synthesis of optically active highly substituted spiro[5,5]undecane-1,5,9-triones was achieved through the reaction of an aldehyde, an enone, and Meldrum's acid in the presence of a catalytic amount of chiral amino acid (see scheme). The Diels–Alder products were obtained as single diastereomers in excellent yields and enantiomeric excesses.