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
Abstract
Carbohydrate-derived 2,3:4,6-diacetonides which are homologated at C-1 by reaction with phenyl acetylide undergo a 6-exo-dig radical cyclization, from a radical located at C-5, to yield highly functionalized cyclohexanes that are correlated with carba-sugars.