Cesium Carbonate-Promoted Reaction of Nitro-Substituted Donor-Acceptor Cyclopropanes with Salicylaldehydes in Water: Access to Chromane Derivatives.

Nitro-substituted donor-acceptor cyclopropanes react with salicylaldehydes in the presence of cesium carbonate in water to give new chromane derivatives. The reaction takes place through in situ formation of allene intermediates from the cyclopropanes and subsequent Michael-initiated ring closure of the intermediates with salicylaldehydes.