METHOD FOR PRODUCTION OF PANTOLACTONE OPTICAL ANTIPODES

• Main Authors: SCHMIDT,JOACHIM,DL, SCHNEIDER,WOLFGANG,DL, BAMBERG,WOLFGANG,DL, WEIGELT,CHRISTIAN,DL
• Format: Patent
• Language: English
• Published: 31.10.1977
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; TRANSPORTING

1395458 Optical resolution of D,L-pantolactone JENAPHARM VEB 29 Oct 1973 [4 June 1973] 50169/73 Heading C2C The optical resolution of D,L-pantolactone is effected by converting the latter into D,L- lithium pantoate, resolving this racemic salt by selective crystallization from a polar solvent (e.g. CH 3 OH, C 2 H 5 OH) or by electrostatic separation of the racemic mixture crystallized from a polar solvent and subsequently converting the optically-active forms of lithium pantoate thus produced into optically-active pantolactone. The undesired optically-active form of lithium pantoate obtained as a by-product is preferably dissolved or suspended in a polar solvent (e.g. H 2 O, CH 3 OH, C 2 H 5 OH) and racemized at an elevated temperature (e.g. 120-180‹ C.) and optionally in the presence of a basic catalyst (e.g. an aliphatic amine or an alkali metal hydroxide or carbonate). The D,L-lithium pantoate is obtained by reacting D,L-pantolactone with a basic lithium compound (e.g. LiOH, Li 2 CO 3 ) in a polar solvent or by the double decomposition of an appropriate pair of salts (e.g. calcium pantoate/lithium oxalate, barium pantoate/lithium sulphate) in an aqueous medium.