Skeletal Editing of Chromone-Fused Dienes to Cyclopropane by Photochemical Carbon Deletion.

A visible-light-driven, photocatalyst-free, air-assisted carbon cleavage of dienes was achieved. Photochemical editing of dienes via an electron donor-acceptor (EDA) complex facilitates direct access to cyclopropane derivatives. This innovative methodology creates an opportunity for the efficient access to valuable cyclopropane derivatives under mild and ambient conditions.