326588-23-2

Upstream product

• 100-39-0 benzyl bromide 
• 17674-16-7 benzyl triflate 
• 372-48-5 2-fluoropyridine 
• 446-26-4 methyl 2-fluoro-3-pyridinecarboxylate 
• 51534-66-8 Methyl α-(methylsulfanyl)butyrate 

Relevant academic research and scientific papers

A short synthesis of camptothecin via a 2-fluoro-1,4-dihydropyridine

Addition of the enolate derived from isopropyl α-(methylsulfanyl)butyrate to N-(quinolylmethyl)-2-fluoropyridinium triflate 7, followed by oxidation-hydrolysis of the resultant 2-fluoro-1,4-dihydropyridine 8b afforded pyridone 9b, from which 20-deoxycampt

Addition of ester enolates to N-alkyl-2-fluoropyridinium salts: Total synthesis of (±)-20-deoxycamptothecin and (+)-camptothecin

Several 4-substituted dihydropyridones or 2-pyridones have been prepared by nucleophilic addition of α-(methylsulfanyl)ester enolates to N-alkyl-2-fluoropyridinium salts, followed by acid hydrolysis or oxidation with concomitant hydrolysis, of the intermediate 2-fluoro-1,4-dihydropyridine adducts, respectively. Addition of the enolate derived from isopropyl α-(methylsulfanyl)butyrate to N-(quinolylmethyl)-2-fluoropyridinium triflate 21 followed by DDQ treatment gave pyridone 29, from which (±)-20-deoxycamptothecin (31), a known precursor of camptothecin, was synthesized by a radical cyclization-desulfurization, with subsequent elaboration of the lactone E ring by chemoselective reduction. A similar sequence starting from the enolate of a chiral 2-hydroxybutyric acid derivative (33) provides access to natural (+)-camptothecin (37).