Studies on the syntheses of sesquiterpene lactones. 15. Syntheses of four possible diastereoisomers of Bohlmann's structure of isoepoxyestafiatin. The stereochemical assignment of isoepoxyestafiatin
摘要:
The stereochemistry of isoepoxyestafiatin was determined to be 1beta,10beta:3alpha,4alpha-diepoxyguaia-11(13)-eno-12,6alpha-lactone by the syntheses of the four possible diastereoisomers 23-26.
The biomimetic synthesis of guaianolide dimers lavandiolides H, I, and K and artematrolide F containing a spirolactone moiety has been accomplished for the first time from naturally abundant arglabin in four to six steps with an overall yield up to 60%, and a series of natural product-like guaianolide dimers, trimer, and tetramer were also successfully synthesized. Notably, the trimeric compound exhibited