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.
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 ... [Show full abstract] steps from the commercially available starting materials, sorbic acid and the requisite α-methylbenzylamine.