FORFARANDE FOR FRAMSTELLNING AV HEXAHYDRO-5-HYDROXI-4-HYDROXIMETYL-2H-CYKLOPENTA (B)-FURAN-2-ONDERIVAT

摘要

The invention relates to a process for the preparation of hexahydro-5-hydroxy-4-hydroxymethyl-2H-cyclopenta[b]furan- 2-one derivatives with the general formula I where Z is a R<1>-C6H4CO group and R<1> is a hydrogen atom, a methyl group, a phenyl group and optionally a nitro group. In this process, a halohydroxyketone is reacted with an acylating agent, where the halohydroxyketone has the general formula II where X is a chlorine, bromine or iodine atom, and the said acylating agent has the general formula R<2>COY, where R1 is an alkyl group with 1-3 carbon atoms and Y is a chlorine or bromine atom or an R<2>-COO group. The reaction is carried out in the presence of tertiary amines and gives an acyl derivative with the general formula III where R<2> and X have the same meaning as above. The acyl derivative obtained is oxidized with a peroxy-acid to prepare the corresponding δ-lactone. This compound is treated with an alkali metal hydroxide to convert it into the corresponding γ-lactone with the general formula V where R<2> has the same meaning as above. The hydroxyl group in the compound with the general formula V is protected by a Z group, where Z has the same meaning as above. This gives a diester, whose selective transesterification leads to the Corey lactone with general formula I. This synthesis can be used for the preparation of prostaglandins.