Conversion Of Two Eremophilane Glucosides From Pittocaulon Praecox Into Eremophilanolides

Two eremophilanolides (3, 4), an aldehyde (6), an intramolecular addition product (7), and two water addition products (8, 9) were obtained by acid treatment of the eremophilane glucosides 10 and 11. A reaction mechanism supported by deuterium labeling is proposed for the conversion of eremophilane glycosides into eremophilanolides.