Abstract
The eudesmanolides vulgarin and peroxyvulgarin were obtained via a biogenetic-type route that involved photo-oxygenation of 1-oxo-5αH,6,11βH-eudesm-3-en-6, 12-olide. The α-face singlet oxygen (
1O
2) attack resulted in the production of peroxyvulgarin as the major product. Stannous chloride reduction of that compound readily yielded vulgarin. These two compounds, vulgarin and peroxyvulgarin, were isolated from
Artemisia abyssinica.