According to the present invention there is provided a method for enantiomeric enrichment of a mixture of two enantiomers of a chiral compound, the method comprises the application of the mixture of two enantiomers of a chiral compound onto a surface of a support material for producing a coated support, the determination a first value of an optical activity (OA.sub.0) of the coated support, the irradiation of the coated support with a light beam having an intensity at least higher than a desorption threshold of one of the enantiomers from the coated support, wherein, if the support material is achiral, the light beam is circularly polarized and, if the support material is chiral, the light beam is unpolarized, linearly polarized or circularly polarized, and the determination of a second value of the optical activity (OA.sub.e) of the coated support after said irradiation, wherein the second value of the optical activity (OA.sub.e) differs from the first value of the optical activity (OA.sub.0).

According to the present invention there is provided a method for enantiomeric enrichment of a mixture of two enantiomers of a chiral compound, the method comprises the application of the mixture of two enantiomers of a chiral compound onto a surface of a support material for producing a coated support, the determination a first value of an optical activity (OA.sub.0) of the coated support, the irradiation of the coated support with a light beam having an intensity at least higher than a desorption threshold of one of the enantiomers from the coated support, wherein, if the support material is achiral, the light beam is circularly polarized and, if the support material is chiral, the light beam is unpolarized, linearly polarized or circularly polarized, and the determination of a second value of the optical activity (OA.sub.e) of the coated support after said irradiation, wherein the second value of the optical activity (OA.sub.e) differs from the first value of the optical activity (OA.sub.0).

The present invention relates to chiral auxiliaries and the syntheses thereof and uses thereof.

The present invention provides a method in which when using (+)-dibenzoyl-D-tartaric acid to optically divide (±)-1-methyl-4-(2,4,6-trimethoxyphenyl)-3-piperidinone, an ether-based solvent is added and an extremely high yield of (R)-1-methyl-4-(2,4,6-trimethoxyphenyl)-3-piperidinone (+)-dibenzoyl-D-tartrate is thereby obtained, a slurry thereof is treated with a base, a “three-dimensionally bulky reducing agent” is subsequently used, and cis-(−)-flocinopiperidol is thereby produced with surprisingly high selectivity.

The present invention provides a method in which when using (+)-dibenzoyl-D-tartaric acid to optically divide (±)-1-methyl-4-(2,4,6-trimethoxyphenyl)-3-piperidinone, an ether-based solvent is added and an extremely high yield of (R)-1-methyl-4-(2,4,6-trimethoxyphenyl)-3-piperidinone (+)-dibenzoyl-D-tartrate is thereby obtained, a slurry thereof is treated with a base, a “three-dimensionally bulky reducing agent” is subsequently used, and cis-(−)-flocinopiperidol is thereby produced with surprisingly high selectivity.

Provided are a novel chitosan compound represented by Formula (I) and a separating agent for optical isomers. In Formula (I), each R is independently a group represented by Formula (II) or a group represented by Formula (III); R.sup.a is an alkyl group having from 1 to 5 carbons or an alkyl group having from 3 to 5 carbons and having a branched chain; and n is an integer of 5 or greater; and in Formulas (II) and (III), each R.sup.b is independently an unsubstituted phenyl group, a phenyl group having a substituent, an unsubstituted cylohexyl group, or a cyclohexyl group having a substituent, and each of the substituent is independently an alkyl group having from 1 to 5 carbons, or a halogen.

The present invention relates to a process for the preparation of a compound (I) or pharmaceutically acceptable salt thereof, which is useful as the key intermediate for the synthesis of compounds for prophylaxis and treatment of a disease associated with the deposition of β-amyloid in the brain, in particular Alzheimer's disease, and other diseases such as cerebral amyloid angiopathy, hereditary cerebral hemorrhage with amyloidosis, Dutch-type (HCHWA-D), multi-infarct dementia, dementia pugilistica and Down syndrome.

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Provided herein are arylcyclohexylamine derivatives and their use in the treatment of psychiatric disorders.

Provided herein are cinchonium betaine catalysts and methods of promoting asymmetric butenolide isomerization reactions using the same.

Provided herein are cinchonium betaine catalysts and methods of promoting asymmetric butenolide isomerization reactions using the same.