Catalyzes a Baeyer-Villiger oxidation reaction, i.e. the insertion of an oxygen atom into a carbon-carbon bond adjacent to a carbonyl, which converts ketones to esters. Can oxidize a wide range of acetophenone derivatives. Highest activity occurs with compounds bearing an electron-donating substituent at the para position of the aromatic ring, e.g. 4-hydroxyacetophenone and 4-aminoacetophenone, leading to the formation of 4-hydroxyphenyl acetate and 4-aminophenyl acetate, respectively. Is also able to oxidize sulfides. 4'-hydroxyacetophenone + H(+) + NADPH + O2 = 4-acetoxyphenol + H2O + NADP(+) Binds 1 FAD per subunit. Inhibited by amino-NADP(+). Optimum pH is 7.5. Optimum temperature is 30 degrees Celsius. Homodimer. The measured mass is that of a monomer in complex with FAD cofactor. Belongs to the FAD-binding monooxygenase family.