119980-66-4

Upstream product

• 67-56-1 methanol 
• 120056-44-2 cis-(1R,3R)-(+)-2-benzyl-3-methoxycarbonyl-1-methoxycarbonylethyl-9-methyl-1,2,3,4-tetrahydro-9H-pyrido<3,4-b>indole 
• 13865-19-5 4-oxobutanoic acid methyl ester 
• 120053-66-9 D-(+)-N_a-methyl-N_b-benzyltryptophan methyl ester 
• 925-57-5 methyl 4-hydroxybutanoate 
• 60702-96-7 2-benzyl-3-(methoxycarbonyl)-9-methyl-1,2,3,4-tetrahydro-9H-pyrido<3,4-b>indole-1-propionic acid 
• 188067-60-9 (R)-methyl 2-amino-3-(1-methyl-1H-indol-3-yl)propanoate 
• 19779-74-9 (R)-3-(1-Methyl-1H-indol-3-yl)-2-{[1-phenyl-meth-(E)-ylidene]-amino}-propionic acid methyl ester 
• 100-52-7 benzaldehyde 

Downstream Products

• 84129-60-2 trans-(1S,3R)-(-)-2-benzyl-3-methoxycarbonyl-1-methoxycarbonylethyl-9-methyl-1,2,3,4-tetrahydro-9H-pyrido<3,4-b>indole 

Relevant academic research and scientific papers

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-CYCLOOCTINDOLE, A TEMPLATE FOR PREPARATION OF MACROLINE/SARPAGINE ALKALOIDS

The synthesis of the tetracyclic ketone was carried out in enantiospecific fashion (>98percent ee) via the 1,3-transfer of chirality from Na-methyl, Nb-benzyl tryptophan methyl ester to the trans diastereomer 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 into the trans isomer occurred stereospecifically under acidic conditions.Dieckmann cyclizatin of either the Na-methyl, Nb-benzyl-cis-(+)-5b or trans-(-)-4b diastereomer provided the cis-bicyclo-azanonane system at approximately the same rate, although the β-keto esters were antipodal, in contrast to results reported in the Na-benzyl series by Magnus.

PICTET-SPENGLER REACTIONS IN APROTIC MEDIA. STEREOSPECIFIC CONVERSION OF OPTICALLY ACTIVE CIS-1,3-DISUBSTITUTED 1,2,3,4-TETRAHYDRO-β-CARBOLINES INTO THEIR CORRESPONDING TRANS DIASTEREOMERS

The Pictet-Spengler reaction in refluxing benzene of D-(+)-Na-methyl-Nb-benzyltryptophan methyl ester 1 and methyl 3-formyl-propionate 2, regioselectively, furnished the trans-1,3-disubstituted-1,2,3,4-tetrahydro-β-carboline 3 (72percent) with no detectable racemization at position-3. The optically active cis-diastereomer 4 (28percent), which accompanied 3, was converted (CH3OH, HCl, heating) into the trans isomer 3 via the ring-cleaved carbocation intermediate 7, followed by stereospecific intramolecular cyclization.