ChemInform Abstract: Reactions of Singlet Oxygen with Alkoxy‐Substituted Dienes. Formation of Dioxetanes in the Singlet Oxygenations of s‐Cis Fixed Dienes (Z,Z)and (E,Z)‐4,5‐Diethylidene‐2,2‐dimethyl‐1,3‐dioxolanes.