Search

Your search keyword '"Lin-Hua Zhang"' showing total 3 results
Start Over Author "Lin-Hua Zhang" Journal heterocycles
3 results on '"Lin-Hua Zhang"'

1. Stereospecificity in the Pictet-Spengler Reaction. Enantiospecific Synthesis of (6S,10S)-(-)-5-Methyl-9-oxo-12-benzyl-6,7,8,9,10,11-hexahydro-6,10-imino-5H-cyclooct[b]indole, a Template for Preparation of Macroline/Sarpagine Alkaloids

Author

James M. Cook, Fu-Xiang Yu, Lin-Hua Zhang, Yingzhi Bi, and Gerald Menzia

Subjects
Pharmacology, Indole test, chemistry.chemical_classification, Pictet–Spengler reaction, Ketone, Stereochemistry, Organic Chemistry, Diastereomer, Aldehyde, Analytical Chemistry, Benzaldehyde, chemistry.chemical_compound, Stereospecificity, chemistry, Chirality (chemistry)
Abstract

The synthesis [from D(+)-tryptophan] of the tetracyclic ketone [(−)-1b] was carried out in enantiospecifc fashion (>98% ee) via the 1,3-transfer of chirality from N a -methyl, N b -benzyl tryptophan methyl ester [(+)-14] to the trans diastereomer [(−)-4b] in the Pictet-Spengler reaction. Although the condensation of 14 with aldehyde (15) in refluxing benzene generated the tetrahydro β-carbolines (4b/5b) in a kinetic ratio (72:28), epimerization (C-1) of the cis diastereomer [(+)-5b] into the trans isomer [(−)-4b] occurred stereospecifically under acidic conditions

Published
1992

2. Pictet-Spengler Reactions in Aprotic Media. Stereospecific Conbersion of Optically Active cis-1,3-Disubstituted 1,2,3,4-tetrahydro-b-carbolines into Their Corresponding trans-Diastereomers

Author

James M. Cook, Lin-Hua Zhang, and James M Cook

Subjects
Pharmacology, chemistry.chemical_compound, Pictet–Spengler reaction, Stereospecificity, Bicyclic molecule, Chemistry, Stereochemistry, Organic Chemistry, Diastereomer, Epimer, Optically active, Benzene, Analytical Chemistry
Abstract

Conversion stereospecifique des produits du titre obtenus par reaction de Pictet-Spengler de l'ester de N-benzyl methyl-1 tryptophane et du formyl-3 propionate de methyle

Published
1988

3. Pictet-Spengler Reactions in Aprotic Media. Nb-Benzyl Promoted Retention of Optical Activity in the Synthesis of an Indole Substituted Azabicyclo[3.3.1]nonane, a Key Template for the Synthesis of Macroline Alkaloids

Author

Lin-Hua Zhang and James M. Cook

Subjects
Pharmacology, Indole test, chemistry.chemical_compound, Pictet–Spengler reaction, Chemistry, Alkaloid, Organic Chemistry, Organic chemistry, Nonane, Benzene, Analytical Chemistry
Abstract

Etude de la synthese de benzyl-12 methyl-5 oxo-9 hexahydro-6,7,8,9,10,11 imino-6,10cycloocta [b] indolecarboxylate-8 de methyle via la reaction de Pictet-Spengler de l'ester de methyle du N-benzyl methyl-1 tryptophane

Published
1988

Catalog

Books, media, physical & digital resources
See catalog results