Abstract: The present invention relates to a novel oxabicycloheptane derivative of the following formula and a pharmaceutically acceptable salt thereof: ##STR1## where D is a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, an arylalkoxy group, an acyloxy group, a dialkylcarbamoyloxy group or an amidoalkyloxy group; B is a substituted or unsubstituted phenyl, thienyl or furyl group; A is the group ##STR2## (where l is 0 or 1; m and n are each 1 or more, provided that m+n is an interger of 2-8; R.sup.1 is an alkylamino group, a dialkylamino group, an arylalkylamino group, a morpholino group, a thiomorpholino group, a 1-pyrrolidinyl group, a piperidino group, an N-alkylpiperazinyl group, an N-hydroxyalkylpiperazinyl or a pyrrolizidinyl group; and R.sup.2 is a lower alkyl group or a hydroxl group), or the group ##STR3## (where l, m, n, R.sup.1 and R.sup.2 are each the same as defined above), or the group ##STR4## (where R.sup.3 and R.sup.