STUDIES ON THE STEREOSTRUCTURE OF EUDESMANOLIDES FROM UMBELLIFERAE - SYNTHESIS OF 11-BETA-ANGELOYLOXY-ALPHA-SANTONIN

The first approach to the synthesis of decipienin A (1) having the ste reostructure b (11 beta-angeloyloxy-alpha-santonin) have been performe d following three different synthetic routes. The key step on the synt hetic procedures is the stereoselective hydroxylation at C-11 position . An evaluation of the different used routes is discussed. Comparison of spectroscopic data of compound 1b and those from the natural decipi enin A suggests that a stereostructure type a could be assigned to the natural product.