16049-29-9

Upstream product

• 16049-28-8 Antirhin 
• 58760-86-4 4-ethyl-7-(2-indol-3-yl-ethyl)-3,4,4a,5,6,7-hexahydro-pyrano[3,4-c]pyridin-1-one 
• 34384-59-3 Acetic acid (2R,12bS)-2-(1,2,3,4,6,7,12,12b-octahydro-indolo[2,3-a]quinolizin-2-yl)-butyl ester 
• 3389-21-7 3-(2-bromoethyl)-1H-indole 
• 34384-59-3 Acetic acid (2S,12bS)-2-(1,2,3,4,6,7,12,12b-octahydro-indolo[2,3-a]quinolizin-2-yl)-butyl ester 
• 61-54-1 tryptamine 
• 84573-50-2 (-)-(1'R,2R,12bS)-2-<1-(Hydroxymethyl)propyl>-1,2,3,4,6,7,12,12b-octahydroindolo<2,3-a>quinolizin-4-one 
• 127218-35-3 4-(1-Acetoxymethyl-propyl)-1-[2-(1H-indol-3-yl)-ethyl]-pyridinium; bromide 
• 127218-33-1 (2S,12bS)-2-(1-Acetoxymethyl-propyl)-1,3,4,6,7,12b-hexahydro-2H-indolo[2,3-a]quinolizine-12-carboxylic acid tert-butyl ester 
• 127218-32-0 2-(1-Acetoxymethyl-propyl)-1,6,7,12b-tetrahydro-4H-indolo[2,3-a]quinolizine-12-carboxylic acid tert-butyl ester 
• 127218-30-8 Acetic acid 2-{2-cyano-1-[2-(1H-indol-3-yl)-ethyl]-1,2,3,6-tetrahydro-pyridin-4-yl}-butyl ester 
• 127218-31-9 Acetic acid 2-(1,4,6,7,12,12b-hexahydro-indolo[2,3-a]quinolizin-2-yl)-butyl ester 
• 22311-05-3 Acetic acid 2-pyridin-4-yl-butyl ester 

Relevant academic research and scientific papers

ALKALOIDS FROM ROOTS OF STRYCHNOS POTATORUM

Twenty-four compounds have been isolated and identified in the root bark of Strychnos potatorum.They are: Harmane carboxamide, cantleyine, 18,19-dihydrousambarensine, polyneuridine, norharmane, akuammidine, nor-C-flurorocurarine, ochrolifuanine A, bisnordihydrotoxiferine, ochrolifuanine E, normacusine B, normavacurine, henningsamine, 11-methoxyhenningsamine, dihydrolongicaudatine, dihydrolongicaudatine Y, anthrhine, (20R)- and (20S)-dihydroantirhine, 11-methoxy-12-hydroxydiaboline, diaboline, 11-methoxydiaboline, desacetylretuline and diaboline N-oxide. Key words: Strychnos potatorum; Loginaceae; root bark; indole alkaloids.

Enantioselective Synthesis of (+)-Dihydroantirhine

Enantioselective synthesis of (+)-dihydroantirhine (3) has been achieved from a readily available chiral starting material, (3S)-cyclopentanone (1), via 2,3-sigmatropic rearrangement.

A Stereodivergent Strategy for Total Syntheses of Antirhine Alkaloids

Total syntheses of the antirhine alkaloids are described. The cyanide-catalyzed imino-Stetter reaction of the aldimine derived from ethyl 2-aminocinnamate and 4-bromopyridine-2-carboxaldehyde provided a 2-pyridinyl substituted indole-3-acetate, which was further converted into the corresponding indoloquinolizidinium intermediate through C-ring formation. Subsequent trans-selective installation of the homoallylic alcohol side-chain at C-15 in the resulting indoloquinolizidinium allowed the total syntheses of antirhine and its known epimer.

General Strategy for the Synthesis of Antirhine Alkaloids: Divergent Total Syntheses of (±)-Antirhine, (±)-18,19-Dihydroantirhine, and Their 20-Epimers

A general synthetic strategy for antirhine alkaloids was developed in this study. The cyanide-catalyzed imino-Stetter reaction of ethyl 2-aminocinnamate and 4-bromopyridine-2-carboxaldehyde afforded the corresponding indole-3-acetic acid derivative. Subsequent formation of the six-membered C ring followed by trans-selective installation of the two-carbon unit at C-15 provided rapid access to the key intermediate. Stereoselective installation of substituents at C-20 allowed the total syntheses of (±)-antirhine, (±)-18,19-dihydroantirhine, and their 20-epimers, all of the known natural products in the antirhine family.

Efficient biomimetic synthesis of indole alkaloids of the vallesiachotamine group by a domino knoevenagel hetero Diels-Alder hydrogenation sequence

An efficient three-step biomimetic synthesis of the four diastereomeric 18,19-dihydroantirhines 4a-d starting from the tetrahydrocarboline aldehydes 5a and 5b is described. Domino reaction of the aldehydes 5a and 5b, respectively, with Meldrum's acid (6) and the enol ethers 8a and 8b in the presence of catalytic amounts of ethylenediammonium diacetate leads to the strictosidine analogues 10a-d and 11a-h, respectively, in 74-86% yield, hydrogenation of which gives mainly 15 and 16 with the skeleton of the vallesiachotamine indole alkaloids (55-86%). In addition, small amounts of 17 and 18 with the corynanthe skeleton are also formed (10-12%). Reduction of both 15 and 16 with LiAlH4 yields the diastereomeric rac-18,19-dihydroantirhines 4a-d in 78-86% yield. VCH Verlagsgesellschaft mbH, 1997.

STEREOSELECTIVE SYNTHESIS OF dl-18,19-DIHYDROANTIRHINE AND dl-3-EPI-18,19-DIHYDROANTIRHINE

A rapid and stereoselective synthesis for both dl-18,19-dihydroantirhine and dl-3-epi-18,19-dihydroantirhine using one and the same starting compound is described.