Reference

Novel chiral ligand and process for preparation of (2R,3R)-2,3-dialkyltartaric acid using the same

Novel chiral ligand and process for preparation of (2R,3R)-2,3-dialkyltartaric acid using the same. Byun, Il Seok; Kim, Sam Min; Kim, Yong Hae (Korea Advanced Institute of Science and Technology, S. Korea). Repub. Korean Kongkae Taeho Kongbo KR 2002017166 A 7 Mar 2002, No pp. given (Korean). (Korea, Republic Of). CODEN: KRXXA7. CLASS: ICM: C07F007-18. APPLICATION: KR 2000-50328 29 Aug 2000. DOCUMENT TYPE: Patent CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) Provided are a novel (2S,3aS,7aS)-2-(t-butyldiphenylsilyloxymethyl)octahydroindoline of the formula(1) and a process for prepg. (2R,3R)-2,3-dialkyltartaric acid by pinacol coupling using it as a chiral ligand, thereby producing (2R,3R)-2,3-dialkyltartaric acid in high chem. and optical yields. (2S,3aS,7aS)-2-(t-butyldiphenylsilyloxymethyl)octahydroindoline is represented by the formula(1), wherein R is Me or Ph, and prepd. 79815-20-6 and 87-69-4 are also in the experiment. by the steps of: converting (S)-indoline-2-carbonic acid into (S)-indoline-2-carbonic acid Et ester using thionyl chloride and ethanol; reducing it by using platinum oxide to obtain (2S,3aS,7aS)-octahydroindole-2-carbonic acid Et ester; reducing it by using lithium aluminum hydride; reacting it with chlorot-butyldiphenylsilane acid in the presence of imidazole to obtain (2S,3aS,7aS)-2-(t-butyldiphenylsilyloxymethyl)octahydroindoline. (2R,3R)-2,3-dialkyltartaric acid is prepd. by the steps of: reacting 2-keto carbonic acid with (2S,3aS,7aS)-2-(t-butyldiphenylsilyloxymethyl)octahydroindoline(I) in the presence of dicyclohexylcarbodiimide(DDC) to obtain 2-ketoamide(II); pinacol coupling the 2-ketoamide(II) in the presence of hexamethylphosphoamide(HMP) to obtain dialkyltartaric acid deriv.; and hydrolyzing the deriv. to manuf. (2R,3R)-2,3-dialkyltartaric acid(III). .

Novel chiral ligand and process for preparing (2S,3S)-2,3-dialkyltartaric acid using the same

Novel chiral ligand and process for preparing (2S,3S)-2,3-dialkyltartaric acid using the same. Byun, Il Seok; Kim, Sam Min; Kim, Yong Hae (Korea Advanced Institute of Science and Technology, S. Korea). Repub. Korean Kongkae Taeho Kongbo KR 2002017165 A 7 Mar 2002, No pp. given (Korean). (Korea, Republic Of). CODEN: KRXXA7. CLASS: ICM: C07F007-18. APPLICATION: KR 2000-50327 29 Aug 2000. DOCUMENT TYPE: Patent CA Section: 27 (Heterocyclic Compounds (One Hetero Atom)) Provided are a novel (S)-2-t-butyldiphenylsilyloxymethylindoline of the formula(1) and a process for prepg. (2S,3S)-2,3-dialkyltartaric acid by pinacol coupling using it as a chiral ligand, thereby producing (2S,3S)-2,3-dialkyltartaric acid in high chem. and optical yields. (S)-2-t-butyldiphenylsilyloxymethylindoline is represented by the formula(1), wherein R is Me or Ph, and prepd. 79815-20-6 and 58479-61-1 are also in the experiment. by the steps of: reducing (S)-indoline-2-carbonic acid into lithium aluminum hydride; reacting it with t-butyldiphenylsilyl chloride compd. in the presence of imidazole to obtain (S)-2-t-butyldiphenylsilyloxymethylindoline. (2S,3S)-2,3-dialkyltartaric acid is prepd. by the steps of: reacting 2-keto carbonic acid with (S)-2-t-butyldiphenylsilyloxymethylindoline(I) in the presence of dicyclohexylcarbodiimide(DDC) to obtain 2-ketoamide(II); pinacol coupling the 2-ketoamide(II) in the presence of hexamethylphosphoamide(HMP) to obtain dialkyltartaric acid deriv.; and hydrolyzing the deriv. to manuf. (2S,3S)-2,3-dialkyltartaric acid(III). .