Caging of Carbonyl Compounds as Photolabile (2,5-Dihydroxyphenyl)ethylene Glycol Acetals.
Aldehydes and ketones caged as 4-(2,5-dihydroxyphenyl)-1,3-dioxolanes are efficiently (Φ = 0.1-0.2) released in a good to excellent chem. yield upon irradn. with 300 nm light. Caged carbonyl compds. are prepd. by their acetalization with (2,5-dimethoxyphenyl)ethylene glycol followed by oxidative demethylation to produce corresponding (1,3-dioxolane-4-yl)-1,4-benzoquinones. The latter acetals are photochem. inert but can be converted into photolabile hydroquinones by mild redn. in situ. [on SciFinder(R)]