4-Hydroxy-2-pyrone derivatives, process for their preparation and their pharmaceutical preparations

Claim 2

Compounds of formula (I); in which; A represents an alkylene group optionally having one or more alkyl substituents or an alkenylene group; and Z represents a substituted or unsubstituted aryl or aryloxy group.

Claim 3

Compounds according to Claim 1, in which: A represents a C 1 or C 2 alkylene group optionally having one or more C 1 - C 3 alkyl substituents or a C 2 or C 3 alkenylene groups and Z represents a phenyl group, a naphthyl group or a tetrahydronaphthyl group optionally substituted by a halogen atom or a C 1 - C 3 alkyl group, or a phenoxy group or a naphthoxy group optionally substituted with a halogen atom.

Claim 4

Compounds as claimed in Claim 2, in which: A represents a methylene, ethylene, methylethylene, dimethylmethylene, vinylene or propenylene group and Z represents a phenyl, naphthyl, tetrahydronaphthyl, phenoxy, naphthoxy, o-chlorophenyl, m-chlorophenyl, p-chlorophenyl, 2,4-dichlorophenyl, 3,5-dichlorophenyl, 2,6-dichlorophenyl, 2-methyl-1-naphthyl, 2-methyl-5,6,7,8-tetrahydro-1-naphthyl, o-chlorophenoxy, m-chlorophenoxy, p-chlorophenoxy, 2,4-dichlorophenoxy, 3,5-dichlorophenoxy or 2,6-dichlorophenoxy group.

Claim 5

Compounds according to Claim 1, selected from: 4-hydroxy-6-[2-(2-methyl-1-naphthyl)ethyl]-3,4,5,6-tetrahydro-2H-pyran-2-one; 4-hydroxy-6-(1-phenoxyethyl)-3,4,5,6-tetrahydro-2H-pyran-2-one; 4-hydroxy-6-[2-(1-naphthy)ethyl] -3,4,5,6-tetrahydro-2H-pyran-2-one; 6-[1-(4-chlorophenoxy)-1-methylethyl]-4-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one; 6-[2-(2,6-dimethyl-1-naphthyl)ethyl]-4-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one; 4-hydroxy-6-[2-(2-methyl-5,6,7,8-tetra- hydro-1-naphthyl)ethyl]-3,4,5,6-tetrahydro-2H-pyran-2-one, 4-hydroxy-6-[1-(2-methylphenyl)ethyl]-3,4,5,6-tetrahydro-2H-pyran-2-one, 6-[1-(2,6-dimethylphenyl)ethyl]-4-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one; 6-[1-(2,6-dichlorophenyl)ethyl]-4-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one; 4-hydroxy-6-[3-(2-methyl-1-naphthyl)propyl]-3,4,5,6-tetrahydro-2H-pyran-2-one; 4-hydroxy-6-[3-(1-naphthyl)propyl]-3,4,5,6-tetrahydro-2H-pyran-2-one; 4-hydroxy-6-(1-phenylethyl)-3,4,5,6-tetrahydro-2H-pyran-2-one; 6-[1-(4-chlorophenyl)ethyl]-4-hydroxy-3,4,5,6-tetrahydro-2H-pyran-2-one; or 6-[1-(2-chlorophenyl)ethyl]-4-hydroxy-3,4,5,6-tetrahydro-2H-2-one. ,

Claim 6

A process for preparing compounds of formula (I), as defined in any one of Claims 1 to 4, which comprises cyclizing a 3,5-dihydroxypentanoic ester of formula (II): (in which A and Z are as defined in Claim 1 and R represents an organic group.'

Claim 7

A process according to Claim 5, in which R represents an alkyl group having from 1 to 4 carbon atoms.

Claim 8

A process according to Claim 5 or Claim 6, in which the cyclization is effected by treating the 3,5-dihydroxypentanoic ester of formula (II) with an alkali and then with a mineral acid.

Claim 9

A pharmaceutical preparation comprising, as active ingredient, at least one compound of formula (I), as claimed in any one of Claims 1 to 4, in admixture with a pharmaceutically acceptable carrier or excipient.

Claim 10

A pharmaceutical preparation as claimed in Claim 8, in a form suitable for oral or parenteral administration.