4850-21-9

Usage

Chemical Description

Quebrachamine is an alkaloid with a complex structure that contains a tertiary nitrogen atom.

Upstream product

• 260444-55-1 (+)-1,2,14,15-tetradehydroaspidospermidine 
• 943739-75-1 (-)-5,16-dioxoquebrachamine 
• 19751-76-9 (+)-1,2-didehydroaspidospermidine 
• 434934-47-1 Allyl-[(1S,6S)-3-(tert-butyl-dimethyl-silanyloxy)-6-ethyl-6-vinyl-cyclohex-2-enyl]-carbamic acid methyl ester 
• 434934-53-9 2-((4aS,11cR)-4a-Ethyl-2,4a,5,6,7,11c-hexahydro-pyrido[3,2-c]carbazol-1-yl)-ethanol 
• 434934-50-6 (4aS,11cR)-4a-Ethyl-2,4a,5,6,7,11c-hexahydro-pyrido[3,2-c]carbazole-1-carboxylic acid methyl ester 
• 434934-48-2 7-(tert-butyl-dimethyl-silanyloxy)-4a-ethyl-4a,5,6,8a-tetrahydro-2H-quinoline-1-carboxylic acid methyl ester 
• 434934-52-8 4a-ethyl-2,4a,5,6,7,11c-hexahydro-1H-pyrido[3,2-c]carbazole 
• 943739-74-0 (R)-3-ethyl-1-(3-indoylacetyl)piperidine-3-acetic acid 
• 943739-73-9 methyl (R)-3-ethyl-1-(3-indoylacetyl)piperidine-3-acetate 
• 943739-71-7 (R)-methyl 2-(3-ethylpiperidin-3-yl)acetate 
• 943739-93-3 (3R)-1-(tert-butoxycarbonyl)-3-ethylpiperidine-3-acetic acid 
• 943739-68-2 (R)-tert-butyl 3-ethyl-3-(2-hydroxyethyl)piperidine-1-carboxylate 
• 943739-66-0 (3R)-3-ethyl-3-(2-hydroxyethyl)-1-[(1S)-2-hydroxy-1-phenylethyl]piperidine 

Downstream Products

• 2671-48-9 (-)-N-methylquebrachamine 

Relevant academic research and scientific papers

Enantioselective Route to Both (+)- and (-)-Enantiomers of Quebrachamine using a Single Chiral Synthon

An enantioselective route to both the (+)- and (-)-enantiomers of the Aspidosperma-type indole alkaloid, quebrachamine, has been established using a single chiral lactone obtained from L-glutamic acid or D-mannitol.

Divergent Asymmetric Total Synthesis of (+)-Vincadifformine, (-)-Quebrachamine, (+)-Aspidospermidine, (-)-Aspidospermine, (-)-Pyrifolidine, and Related Natural Products

A uniformly strategic total synthesis of Aspidosperma alkaloids (+)-vincadifformine, (-)-quebrachamine, (+)-aspidospermidine, (-)-aspidospermine, (-)-pyrifolidine, and nine others from efficiently constructed tricyclic ketone 13 is reported. Highlights of these divergent and practical syntheses include (i) stereoselective intermolecular [4 + 2] cycloaddition to establish a C-E ring with one all-carbon quaternary stereocenter (C-5) and two bridged contiguous cis-stereocenters (C-12 and C-19), (ii) a Pd/C-catalyzed hydrogenation/deprotection/amidation cascade process to assemble the D ring, and (iii) Fischer indolization to forge the A-B ring.

Enantioselective synthesis of 3,3-disubstituted piperidine derivatives by enolate dialkylation of phenylglycinol-derived oxazolopiperidone lactams

(Chemical Equation Presented) The stereochemical outcome of the enolate dialkylation of simple phenylglycinol-derived oxazolopiperidone lactams is studied. High stereoselectivities in the generation of the quaternary stereocenter are obtained by the appropriate choice of both the configuration of the starting lactam and the order of introduction of the substituents. The usefulness of the methodology is illustrated by the conversion of some of the dialkylated lactams into known synthetic precursors of alkaloids and by the total synthesis of (-)-quebrachamine.

An efficient approach to Aspidosperma alkaloids via [4 + 2] cycloadditions of aminosiloxydienes: Stereocontrolled total synthesis of (±)-tabersonine. Gram-scale catalytic asymmetric syntheses of (+)-tabersonine and (+)-16-methoxytabersonine. Asymmetric syntheses of (+)-aspidospermidine and (-)-quebrachamine

Described is a concise, highly stereocontrolled strategy to the Aspidosperma family of indole alkaloids, one that is readily adapted to the asymmetric synthesis of these compounds. The strategy is demonstrated by the total synthesis of (±)-tabersonine (rac-1), proceeding through a 12-step sequence. The basis for this approach was provided by a highly regio- and stereoselective [4 + 2] cycloaddition of 2-ethylacrolein with 1-amino-3-siloxydiene developed in our laboratory. Subsequent elaboration of the initial adduct into the hexahydroquinoline DE ring system was accomplished efficiently by a ring-closing olefin metathesis reaction. A novel ortho nitrophenylation of an enol silyl ether with (o-nitrophenyl)phenyliodonium fluoride was developed to achieve an efficient, regioselective introduction of the requisite indole moiety. The final high-yielding conversion of the ABDE tetracycle into pentacyclic target rac-1 relied on intramolecular indole alkylation and regioselective C-carbomethoxylation. Our approach differs strategically from previous routes and contains built-in flexibility necessary to access many other members of the Aspidosperma family of indole alkaloids. The versatility of the synthetic strategy was illustrated through the asymmetric syntheses of the following Aspidosperma alkaloids: (+)-aspidospermidine, (-)-quebrachamine, (-)-dehydroquebrachamine, (+)-tabersonine, and (+)-16-methoxytabersonine. Of these, (+)-tabersonine and (+)-16-methoxytabersonine were synthesized in greater than 1 -g quantities and in enantiomerically enriched form (～95% ee). The pivotal asymmetry- introducing step was a catalyzed enantioselective Diels-Alder reaction, which proceeded to afford the cycloadducts in up to 95% ee. Significantly, the synthetic sequence was easy to execute and required only four purifications over the 12-step synthetic route.