Introduction and background.- Discovery of the double 3]2] photocycloaddition.- A brief discussion on fenestranes.- Investigation of the double 3]2] photocycloaddition reaction for the synthesis of fenestranes.- Attempted synthesis of a "criss-cross" double 3]2] photocycloadduct.- Attempts toward the synthesis of alternative structures via the double 3]2] photocycloaddition.- Conclusion.- Experimental.- References.- Appendix I.