A chemo-enzymatic route to differentially protected aryl-naphthalenes.

Aryl-naphthalene diacetates prepared from bispropargyl sulfones, ethers and amines via Garratt-Braverman Cyclization have been selectively hydrolysed by AK lipase to the monoacetates 12a-c in high yields. The regioisomeric mono acetates 13a-c have been prepared by acetylation of the corresponding diols using the same enzyme. In both cases, the more exposed acetoxymethyl or hydroxy methyl attached to the naphthalene ring binds to the active site of the enzyme and underwent hydrolysis/acetylation. The method provides easy access to differentially protected aryl-naphthalenes which should allow further modifications.