β-ELIMINATION IN ALDONOLACTONES. THE CONVERSION OF L-RHAMNONO-1,5-LACTONE INTO 3-BENZOYLOXY-6-METHYLPYRAN-2-ONE

Article abstract of DOI:10.1016/S0008-6215(00)83833-1

Benzoylation of L-rhamnono-1,5-lactone (1) for 90 min at room temperature afforded 2,3,4-tri-O-benzoyl-L-rhamnono-1,5-lactone (2).When an excess of benzoyl chloride and pyridine was used for 20 h, with subsequent sublimation of benzoic acid from the mixture at 120 deg C in vacuo, a double elimination took place and 3-benzoyloxy-6-methylpyran-2-one (4) was isolated as the main product.The conversion of 1,2, and 2,4-di-O-benzoyl-3,6-dideoxy-L-erythro-hex-2-enono-1,5-lactone (3) into the pyran-4-one derivative 4 under different conditions was monitored chromatographically.