265652-18-4

Upstream product

• 110-86-1 pyridine 
• 434308-76-6 (1'S,2'R)-2,6-dimethoxy-4-[2'-dibenzylamino-1'-(tert-butyldimethylsilanyloxy)-4'-trityloxybutyl]pyrimidine 
• 434308-80-2 C₃₄H₅₃BrN₄O₇Si 
• 434308-90-4 (3R,4aS,6S,7R,8S)-8-Azidomethyl-3-[(S)-(tert-butyl-dimethyl-silanyloxy)-(2,6-dimethoxy-pyrimidin-4-yl)-methyl]-7-methyl-6-triethylsilanyloxy-octahydro-pyrido[1,2-c]pyrimidin-1-one 
• 434309-04-3 (3R,4aS,6S,7R,8S)-8-(4-Bromo-benzyloxymethyl)-3-[(S)-(tert-butyl-dimethyl-silanyloxy)-(2,6-dimethoxy-pyrimidin-4-yl)-methyl]-6-hydroxy-7-methyl-octahydro-pyrido[1,2-c]pyrimidin-1-one 
• 434309-02-1 (3R,4aS,7R,8S)-8-(4-Bromo-benzyloxymethyl)-3-[(S)-(tert-butyl-dimethyl-silanyloxy)-(2,6-dimethoxy-pyrimidin-4-yl)-methyl]-7-methyl-hexahydro-pyrido[1,2-c]pyrimidine-1,6-dione 
• 434308-74-4 (1'S,2'R)-2,6-dimethoxy-4-(2'-dibenzylamino-1'-hydroxy-4'-trityloxybutyl)pyrimidine 
• 434308-72-2 (R)-2,6-dimethoxy-4-(2'-dibenzylamino-4'-trityloxybutanoyl)pyrimidine 
• 434308-88-0 (3R,4aS,6S,7R,8S)-8-Azidomethyl-3-[(S)-(tert-butyl-dimethyl-silanyloxy)-(2,6-dimethoxy-pyrimidin-4-yl)-methyl]-6-hydroxy-7-methyl-octahydro-pyrido[1,2-c]pyrimidin-1-one 
• 434308-86-8 JH₀₉₂₆₀₁ 
• 434308-98-2 (1'S,2'R)-2,6-dimethoxy-4-[2'-dibenzylamino-1'-(tert-butyldimethylsilanyloxy)-4'-hydroxybutyl]pyrimidine 
• 434309-00-9 (1'S,2'R)-2,6-dimethoxy-4-[2'-(tert-butyloxycarbonyl)amino-1'-(tert-butyldimethylsilanyloxy)-4'-hydroxybutyl]pyrimidine 
• 434308-70-0 (3R)-3-dibenzylamino-2-hydroxy-2-(2,6-dimethoxypyrimidin-4-yl)tetrahydrofuran 
• 434308-58-4 (3R,4S)-3-(tert-butyloxycarbonyl)amino-4-(tert-butyldimethylsilanyloxy)-4-(2,6-dimethoxypyrimidin-4-yl)butanal 

Relevant academic research and scientific papers

Short Total Synthesis of [15N5]-Cylindrospermopsins from 15NH4Cl Enables Precise Quantification of Freshwater Cyanobacterial Contamination

Fresh water cyanobacterial algal blooms represent a major health risk because these organisms produce cylindrospermopsin, a toxic, structurally complex, zwitterionic uracil-guanidine alkaloid recognized by the EPA as a dangerous drinking water contaminant. At present, the ability to detect and quantify the presence of cylindrospermospin in water samples is severely hampered by the lack of an isotopically labeled standard for analytical mass spectrometry. Herein, we present a concise, scaled total synthesis of 15N cylindrospermosin from 15N ammonium chloride, which leverages a unique stereoselective intramolecular double conjugate addition step to assemble the tricyclic guanidine core. In addition to providing the first pure isotopically labeled probe for precise quantification of this potent biotoxin in fresh water sources, our results demonstrate how unique constraints associated with isotope incorporation compel novel solutions to synthesis design.

Syntheses of the cylindrospermopsin alkaloids

An intramolecular 1,3-dipolar cycloaddition has efficiently constructed the A-ring portions of the cylindrospermopsin alkaloids. A nitro-aldol addition of an elaborated nitroalkane to a pyrimidine aldehyde followed by an intramolecular reductive guanidiny

Total synthesis of (-)-7-epicylindrospermopsin, a toxic metabolite of the freshwater cyanobacterium Aphanizomenon ovalisporum, and assignment of its absolute configuration

(Chemical Equation Presented) The Z and E nitrones 38 and 39 from condensation of aldehyde 20 with hydroxylamine 36 underwent intramolecular dipolar cycloaddition to give the substituted 1-aza-7-oxobicyclo[2.2.1] heptanes 40 and 41 in a ratio of 2:1, respectively. Reductive N-O bond cleavage of 40 followed by carbonylation gave cyclic urea 47 in which inversion of the secondary alcohol was effected via an oxidation-reduction sequence. After conversion of the p-bromobenzyl ether 50 to azide 54, activation of the cyclic urea as its O-methylisourea and reduction of the azide led to spontaneous cyclization to afford the tricyclic nucleus 59 of cylindrospermopsin. Global deprotection, including hydrolysis of the 2,4-dimethyoxypyrimidine appendage to a uracil, and then monosulfation of the resultant diol 60 afforded a substance identical with natural (-)-7-epicylindrospermopsin (1). The asymmetric synthesis of (-)-7-epicylindrospermopsin defines its absolute configuration as 7S,8R,10S,12S,13R,14S.