Branched-chain sugars. Part 8. The synthesis of C-acetylpyranosides and a pillarose derivative using 1-methoxyvinyl-lithium

Abstract

1-Methoxyvinyl-lithium, a masked acylating agent, added to the protected hexopyranosiduloses (1), (4), and (7) to give adducts that were readily hydrolysed with acid to the C-acetyl derivatives (3), (6), and (9), respectively. The 1-methoxyvinyl adduct (13) derived from methyl 2,3,6-trideoxy-α-L-glycero-hexopyranosid-4-ulose (12) gave methyl 4²-O-benzoyl-α-L-pillaroside (16), following oxidation with m-chloroperbenzoic acid in wet ether and benzoylation of the resulting 4-C-glycoloyl derivative (15).