Photolabile protection of alcohols, phenols, and carboxylic acids with 3-hydroxy-2-naphthalenemethanol.

Irradiation of alcohols, phenols, and carboxylic acids “caged” with the (3-hydroxy-2-naphthalenyl)methyl group results in fast (krelease ≈ 105 s−1) release of the substrates with good quantum (Φ = 0.17−0.26) and chemical (>90%) yields. The initial byproduct of the photoreaction, 2-naphthoquinone-3-methide, reacts rapidly with water (kH2O = 144 ± 11 s−1) to produce parent 3-hydroxy-2-naphthalenemethanol. The o-quinone methide intermediate can be also trapped by other nucleophiles or converted into a photostable Diels−Alder adduct with ethyl vinyl ether.