Concise total asymmetric syntheses of (-)-fagomine, two of its epimers, and two seven-membered ring congeners
Csatayová K., Davies SG., Fletcher AM., Ford JG., Klauber DJ., Roberts PM., Thomson JE.
Abstract Diastereoselective syn- and anti-dihydroxylations of enantiopure tetrahydropyridine and tetrahydroazepine scaffolds have been used in total asymmetric syntheses of the polyhydroxylated azacycles (-)-fagomine, (-)-3-epi-fagomine, (-)-5-epi-fagomine and two related polyhydroxylated azepanes. In each case, the target compounds were isolated as single diastereoisomers (>99:1 dr) in fewer than eight steps from the commercially available starting materials, sorbic acid and the requisite α-methylbenzylamine.