Studies Relevant to Ellagitannin Chemistry: Strain-Energy Induced Opening of the D-Glucono-#delta#-lactone Ring of an Ellagitannin Derivative and the Synthesis of Ellagitannin Natural Products with a D-Gluconic Acid Moiety

摘要

The opening or the D-glucono-#delta#-lactone ring of the ellagitannin derivative 8, which contains a hexabenzyloxydiphenoly moiety, to the corresponding gluconic acid derivative 9 under mild acidic conditions was investigated. This transformation was found to occur quantitatively upon treatment of the D-glucono-#delta#-lactone derivative 8 with silica gel.