New strategy for the synthesis of iminoglycitols from amino acids.
A novel strategy for the enantioselective synthesis of polyhydroxypiperidines, which can be considered as iminoglycitols or 2,6-dideoxyazasugars, was developed. alpha-Benzolsulfonylamino esters served as a C(2)N building block while 2-bromo-3-(bromomethyl)oxazoles and -thiazoles contributed a C3-unit to the final piperidine ring. At first a dihydropyridine ring was established via alkylation and bromine-lithium exchange. The keto group of the resulting 5,6-dihydro[1,3]oxazolo- and 5,6-dihydro[1,3]thiazolo[4,5-c]pyridin-7(4H)-ones was reduced and, after alkylation reactions, the azole ring was cleaved, thus providing heteroatom substituents for the target piperdines. Protected 5-amino-3,4-dihydroxy and 5-amino-3-hydroxy-4-thiohydroxypiperdines were obtained in the talose series while Mitsunobu reaction of the intermiediates provided access to the altrose series.
Swaleh
Sauda
S
Institut für Chemie, Humboldt-Universität Berlin, Brook-Taylor-Strasse 2, D-12489 Berlin, Germany. liebscher@chemie.hu-berlin.de
Liebscher
Jürgen
J
D000596:Amino Acids / Q000737:chemistry*; D002625:Chemistry, Organic / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D006863:Hydrogen-Ion Concentration; D007097:Imines / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D010880:Piperidines / Q000138:chemical synthesis* / Q000737:chemistry; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
D000596:Amino Acids; D007097:Imines; D010880:Piperidines; D011725:Pyridines