TRANSANNULAR CYCLIZATION OF THE E,E-GERMACRADIENOLIDE HANPHYLLIN

Article abstract of DOI:10.1007/BF00630647

The results are reported of the interaction of the trans,trans-germacradienolide hanphyllin with m-chloroperbenzoic acid and with 50percent sulfuric acid.This leads to a cyclization reaction with the formation of eudesmanolides: 1β-hydroxy-3-oxo-1,4,5,7α(H),6β(H)-eudesm-11(13)-en-6,12-olide, ridentin B, and 3β-hydroxy-5,7α(H),6β(H)-eudesma-4(15),11(13)-dien-6,12-olide; and also products of the opening of the lactone ring as a consequence of transeterification.The structures of the compounds obtained are discussed on the basis of spectral results (IR, PMR, and mass spectra) and of x-ray structural analysis.