Wavelength dependent photoextrusion and tandem photo-extrusion reactions of ninhydrin bis-acetals for the synthesis of 8-ring lactones, benzocyclobutenes and orthoanhydrides.

Ninhydrin bis-acetals give access to 8-ring lactones, benzocyclo-butenes and spirocyclic orthoanhydrides through photoextrusion and tandem photoextrusion reactions. Syntheses of fimbricalyxlactone B, isoshihunine and numerous biologically-relevant heterocycles show the value of the methods, while TA-spectroscopy and TD-DFT studies provide mechanistic insights on their wavelength dependence.