In a process for producing hydroperoxides, an alkylaromatic compound of general formula (I): in which R1 and R2 each independently represents an alkyl group having from 1 to 4 carbon atoms, provided that R1 and R2 may be joined to form a cyclic group having from 4 to 10 carbon atoms, said cyclic group being optionally substituted, and R3 represents hydrogen, one or more alkyl groups having from 1 to 4 carbon atoms or a cyclohexyl group, with oxygen in the presence of a catalyst comprising a manganese oxide molecular sieve to produce a hydroperoxide of general formula (II): in which R1, R2 and R3 have the same meaning as in formula (I). The hydroperoxide of formula (II) may then be converted to a phenol and an aldehyde or a ketone of the general formula R1COCH2R2 (III), in which R1 and R2 have the same meaning as in formula (I). In the case where the ketone is cyclohexanone, this may then be dehydrogenated to produce further phenol.