A compound represented by general formula (IA) or a salt thereof useful as a fluorescent probe for zinc: wherein R.sup.1 and R.sup.2 represent a hydrogen atom or a group represented by formula (A), wherein X.sup.1, X.sup.2, X.sup.3, and X.sup.4 represent a hydrogen atom, an alkyl group, a 2-pyridylmethyl group, or a protective group for an amino group, and m and n represent 0 or 1 provided that R.sup.1 and R.sup.2 do not simultaneously represent hydrogen atoms; R.sup.3 and R.sup.4 represent a hy...

This invention provides novel benzopyran derivatives of the formula ##STR1## wherein R is an alkyl group of 3-10 carbon atoms. The compounds of this invention are useful as antihypertensive agents.

1,9-Dihydroxy-3-alkyl-6a,7,8,9,10,10a-hexahydro-6H-dibenzo[b,d]pyrans, useful as hypotensive agents, as psychotropic drugs, particularly as anti-anxiety and/or antidepressant drugs, and as sedative and/or analgesic drugs.

Reaction of an O-methyl or O-ethyl resorcinol with a cyclohexene carbinol derivative in the presence of a catalyst affords a 6a,10a-trans-1-methoxy or 1-ethoxy-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-dibenzo[b,d]pyran-9-one derivative.

Reaction of a 5-substituted resorcinol with a 1-alkoxy-4-(1-hydroxy-1-methylethyl)-1,4-cyclohexadiene in the presence of a suitable catalyst affords the corresponding dl-cis-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-d ibenzo[b,d]pyran-9-one.

Reaction of 4-(1-hydroxy-1-methylethyl)-3-cyclohexen-1-one with a 5-substituted resorcinol in the presence of boron tribromide, boron trifluoride or stannic chloride provides, depending upon the duration of reaction, either a 2,7-dihydroxy-5-isopropylidene-9-substituted-2,6-methano-3,4,5,6-tetrahydr o-2H-1-benzoxocin or a 6a,10a-cis-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro- 9H-dibenzo[b,d]pyran-9-one.

Reaction of a 5-substituted resorcinol with a 1-alkoxy-4-(1-hydroxy-1-methylethyl)-1,4-cyclohexadiene in the presence of a catalyst such as boron tribromide, boron trifluoride or stannic chloride, and in the presence of about an equimolar quantity of water, affords predominantly a cis-hexahydrodibenzopyranone in high yields.

Reaction of cis-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-dibe nzo[b,d]pyran-9-ones with an aluminum halide in an unreactive organic solvent effects complete epimerization to provide the corresponding trans-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-di benzo[b,d]pyran-9-one.

Reaction of a 5-substituted resorcinol with optically active apoverbenone in the presence of aluminum chloride affords an optically active trans-1-hydroxy-3-substituted-6,6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H-di benzo[b,d]pyran-9-one.

Stable polymorphic crystalline form of trans-dl-1-hydroxy-3-(1',1'-dimethylheptyl)-6,6-dimethyl-6,6a,7,8,-10,10a- hexahydro-9H-dibenzo[b,d]pyran-9-one, capable of producing significant blood levels in mammals for long periods of time after oral administration of the drug.