Synthesis of Pyranopyrans Related to Diplopyrone and Evaluation as Antibacterials and Herbicides.

Stereoselective syntheses of new pyranopyrans that are related to the natural product diplopyrone, which is a phytotoxin implicated in cork oak decline, have been achieved from carbohydrate starting materials in two approaches that are based on -glycosides as key intermediates. A -alkynyl glycoside prepared by Ferrier rearrangement was used as the precursor to a new pyranopyran alkyne that showed potent antibacterial activity against the common bacterial pathogen that causes enteric septicemia in catfish. The -alkynyl glycoside also showed herbicidal activity.