INVESTIGADORES
VARELA Oscar Jose
artículos
Título:
Synthesis of enantiomerically pure enones (2-benzyloxypyran-3-ones) derived from pentoses
Autor/es:
L. DADA; VERÓNICA E. MANZANO; O. VARELA
Revista:
CARBOHYDRATE RESEARCH
Editorial:
ELSEVIER SCI LTD
Referencias:
Lugar: Amsterdam; Año: 2019
ISSN:
0008-6215
Resumen:
The useful synthons sugar enones (2-benzyloxypyran-3-ones) derived from pentoses have been prepared startingfrom 2-acetoxyglycals or benzyl pentopyranosides. The glycals were glycosylated with benzyl alcohol in thepresence of a Lewis acid (SnCl4 or InCl3) to give enantioenriched enones (ee=80?90%). Under catalysis withInCl3, benzyl 2-enopyranosides gave also the enones (ee=87%). On the other hand, enantiomerically pureenones were synthesized via an improved straightforward and high yielding sequence (70% overall) from benzylpentopyranosides. However, the yields of both, the glycosylation of glycals as well as some specific reactions ofthe sequence from glycosides, were lowered when a p-nitro substituent was introduced into the benzyl group.These routes became impractical in the case of p-acetamidobenzyl derivatives, because of the large extent ofdecomposition. Therefore, alternative sequences have been developed for the synthesis of 2-(p-acetamidobenzyloxy)pyran-3-ones.
