Process for the separation of racemic alkali metal salts and of the lactone of cis-2-hydroxycyclopent-4-en-1-ylacetic acid

摘要

An alkali metal salt or the lactone of racemic cis-2-hydroxycyclopent-4-en-1-ylacetic acid is reacted with optically active alpha -phenylethylamine. The part of the resultant pair of diastereomeric salts precipitated from the reaction mixture is converted into the corresponding optically active lactone, or into the corresponding optically active salt of cis-2-hydroxycyclopent- 4-en-1-ylacetic acid. The mother liquor of the reaction mixture obtained is acidified and the resultant cis-2-hydroxycyclopent-4-en- 1-ylacetolactone is hydrolysed. The precipitated alkali metal salt of the racemic cis-2-hydroxycyclopent-4-en-1-ylacetic acid is separated off. Finally, the mother liquor is hydrolysed using an alkali metal hydroxide and the precipitated alkali metal salt of the antipode of cis-2-hydroxycyclopent-4-en-1-ylacetic acid, which is opposite to the diastereomeric salt which was precipitated by the separating agent, is separated off.