New Strategy for the Synthesis of Iminoglycitols from Amino Acids
2002; American Chemical Society; Volume: 67; Issue: 10 Linguagem: Inglês
10.1021/jo010665z
ISSN1520-6904
AutoresSauda Swaleh, Jürgen Liebscher,
Tópico(s)Chemical Synthesis and Analysis
ResumoA novel strategy for the enantioselective synthesis of polyhydroxypiperidines, which can be considered as iminoglycitols or 2,6-dideoxyazasugars, was developed. α-Benzolsulfonylamino esters served as a C2N 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.
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