ChemInform Abstract: A Novel Entry to 5a-Carba-hexopyranoses from Carbohydrates Based on a 6-exo-dig Radical Cyclization: Synthesis of 5a-Carba-β-D-mannopyranose Pentaacetate.

✍ Scribed by Ana M. Gomez; Gerardo O. Danelon; Eduardo Moreno; Serafin Valverde; J. Cristobal Lopez

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 38 KB
• Volume: 30
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199921205

✦ Synopsis

A Novel Entry to 5a-Carba-hexopyranoses from Carbohydrates Based on a 6-exo-dig Radical Cyclization: Synthesis of 5a-Carbaβ-D-mannopyranose Pentaacetate.

-Mannose-derived diacetonide (VI) undergoes a 6-exo-dig radical cyclization to give highly functionalized cyclohexanes which are correlated with carba-sugars. This method has the following advantages: the choice of a diacetonide reduces the protecting group manipulations, unlike other approaches to carba-sugars from carbohydrates, in this pathway the hexose is correlated with its corresponding carba-pyranoside; the selection of phenylacetylide (II) as the radical acceptor is made on the basis of the beneficial effects of the phenyl group in alkyne cyclizations. -(GOMEZ,