A compound of formula (I) F wherein R.sup.1 represents a hydrocarbon group which may be substituted or a heterocyclic group which may be substituted; x represents a bond, an oxygen atom, a sulfur atom, or a group of the formula: --CO--, --CS--, --CR.sup.4(OR.sup.5)-- or --NR.sup.6-- wherein each of R.sup.4 and R.sup.6 represents a hydrogen atom or a hydrocarbon group which may be stubstituted, R.sup.5 represents a hydrogen atom or a protective group for a hydroxyl group; m represents an integer of 0 to 3; Y represents an oxygen atom, a sulfur atom, or a group of the formula: --SO--, --SO.sub.2--, --NR.sub.7--, --CONR.sub.7-- or --NR.sup.7CO-- wherein R.sup.7 represents a hydrogen atom or a hydrocarbon group which may be substituted; ring A represents an aromatic ring which may further have 1 to 3 substituents; n represents an integer of 1 to 8; ring B represents a nitrogen-containing 5-membered hetero ring which may further be substituted by an alkyl group.