697222-83-6

Upstream product

• 4299-70-1 L-tryptophan methyl ester 
• 219558-86-8 2--3-<2(S)-(methoxycarbonyl)-2-b-(tert-butoxycarbonyl)-N^b-benzylamino>ethyl>indole 
• 219558-95-9 2-<(methoxycarbonyl)methyl>-3-<2(S)-(methoxycarbonyl)-2-b-(tert-butoxycarbonyl)-N^b-benzylamino>ethyl>indole 
• 219558-74-4 methyl N^α-benzyl-N^α-(tert-butoxycarbonyl)-L-tryptophanate 
• 100-52-7 benzaldehyde 
• 19779-75-0 N_b-benzylidene-L-tryptophan methyl ester 
• 63229-68-5 methyl N-benzyl-L-tryptophanate 
• 7524-52-9 (S)-tryptophan methyl ester hydrochloride 
• 18778-96-6 (2E)-4,4-dimethoxybut-2-enal 
• 219557-56-9 2-<(methoxycarbonyl)methyl>-3-<2-(S)-(methoxycarbonyl)-2-(N^b-benzylamino)ethyl>indole 

Downstream Products

• 219558-21-1 (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-5-(1ξ-hydroxy-2-(1-ethoxyethoxy))ethyl-1H-pyrrolo<2,3-d>carbazole-6-carboxylate 
• 219558-31-3 (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-5-(2-(1-ethoxyethoxy)acetyl)-1H-pyrrolo<2,3-d>carbazole-6-carboxylate 
• 219557-77-4 (2S,3aS,5R,11bR)-3-Benzyl-2-cyano-5-dimethoxymethyl-2,3,3a,4,5,7-hexahydro-1H-pyrrolo[2,3-d]carbazole-6-carboxylic acid methyl ester 
• 219558-45-9 (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-5-(2-hydroxyacetyl)-1H-pyrrolo<2,3-d>carbazole-6-carboxylate 
• 219557-83-2 (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-5-(dimethoxymethyl)-1H-pyrrolo<2,3-d>carbazole-6-carboxylate 
• 219557-47-8 (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-5-formyl-1H-pyrrolo<2,3-d>carbazole-6-carboxylate 
• 219557-69-4 (-)-methyl (2S,3aS,5R,11bR)-2-(aminocarbonyl)-3-benzyl-2,3,3a,4,5,7-hexahydro-5-(dimethoxymethyl)-1H-pyrrolo<2,3-d>carbazole-6-carboxylate 

Relevant academic research and scientific papers

Syntheses of strychnan- and aspidospermatan-type alkaloids. 10. An enantioselective synthesis of (-)-strychnine through the Wieland-Gumlich aldehyde

Condensations of L-tryptophan-derived 2-[(methoxycarbonyl)methyl]-3- [2(S)-(benzyloxycarbonyl)-2-(N(b)-benzylamino)ethyl]indole (6) with 4,4- dimethoxyacrolein or with 2,4-hexadienal, followed by removal of the tryptophanyl ester function, respectively gave the tetracyclic acetal (-)- methyl (2S,-3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-5- (dimethoxymethyl)-1H-pyrrolol[2,3-d]carbazole-6-carboxylate (10) or the tetracyclic olefin (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7- hexahydro-5-(1-propenyl)-1H-pyrrolo[2,3-d]carbazole-6-carboxylate (14). Their respective hydrolysis or oxidation provided, enantioselectively, the tetracyclic aldehyde (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7- hexahydro-5-formyl-1H-pyrrolo[2,3-d]carbazole-6-carboxylate (5). Its reaction with tri-n-butyl-1-(ethoxy)ethoxymethyltin and n-butyllithium, followed by oxidation of the resultant alcohol (-)-methyl (2S,3aS,5R,11bR)-3-benzyl- 2,3,3a,4,5,7-hexahydro-5-(1ξ-hydroxy-2-((1-ethoxy-ethoxy))ethyl-1H- pyrrolo[2,3-d]carbazole-6-carboxylate (16) and cyclization furnished the pentacyclic ketone (-)-methyl (2S,3aS,SR,11bR)-3-benzyl-2,3,3a,4,5,7- hexahydro-3,5-ethano-12-oxo-1H-pyrrolo-[2,3-d]carbazole-6-carboxylate (15). A Horner-Emmons condensation led to the unsaturated esters (-)-methyl (2S,3aS,5R,11bR)-3-benzyl-2,3,3a,4,5,7-hexahydro-3,5-ethano-12-(E and Z)- [(methoxycarbonyl)-methylene]-1H-pyrrolo[2,3-d]carbazole-6-carboxylates (19 and 20) with 17:1 E/Z selectivity. Reductions of the ester and vinylegous urethane functions in 19 led to the Wieland-Gumlich aldehyde 3 as a 6:1 anomeric hemiacetal mixture. Its condensation with malonic acid provided (- )-strychnine (1) in 5.3% overall yield and 14 steps from the tryptophan derivative 6.