Compounds of the general formula (I): or a salt thereof, wherein R.sup.1 is a hydrogen atom or the like; R.sup.2 is NHSO.sub.2R.sup.3 or the like; R.sup.3 is a (C.sub.1-C.sub.6)alkyl group or the like; R.sup.5 is a hydrogen atom or the like; R.sup.6 and R.sup.7 may be the same or different and are each independently a hydrogen atom or the like; X is an oxygen atom or the like; Y is an oxygen atom or the like; Z.sup.1 to Z.sup.6 are a carbon atom or the like; n is an integer of 0 to 6; *1 is an asymmetric carbon atom; and *2 is an asymmetric carbon atom when R.sup.5 is other than a hydrogen atom.