Scheme 15.

Redox level-independent cycloaddition to form a γ-lactone.a
aYields are of material isolated by flash chromatography on silica gel. C10H15CO2H = 1-adamantanecarboxylic acid. dppp = bis-(diphenylphosphino)propane.

Redox level-independent cycloaddition to form a γ-lactone.a
aYields are of material isolated by flash chromatography on silica gel. C10H15CO2H = 1-adamantanecarboxylic acid. dppp = bis-(diphenylphosphino)propane.