Branched-chain sugars. Part 7. A route to sugars with two-carbon branches using 1-methoxyvinyl-lithium

Abstract

1,2:5,6-Di-O-isopropylidene-α-D-ribo-hexofuranos-3-ulose (11) reacted with 1-methoxyvinyl-lithium in tetrahydrofuran-n-pentane at –60 °C to give a crystalline adduct identified as 1,2:5,6-di-O-isopropylidene-3-C-(1-methoxyvinyl)-α-D-allofuranose (12). The sugar derivatives (13), (14), (16), and (18), which contain a variety of two-carbon branches, were readily derived from the adduct (12).