Syntheses of 2,5-Disubstituted Dihydrofurans from γ-Substituted Chiral Allenamides

Details of a synthesis of dihydrofurans using γ-substituted chiral allenamides are described here.
Some transformations of these dihydrofurans are also examined including a highly stereoselective
dihydroxylation and a rare account of a Lewis acid-mediated removal of an N-acyl substituent at
the anomeric carbon of a tetrahydrofuran ring system. These studies provide further support for
the synthetic utility of allenamides.