Km. Turdybekov et al., PHOTOCHEMICAL TRANSFORMATION OF HANPHILLINE AND CRYSTAL-STRUCTURE OF 1(10)Z,4Z-HANPHILLINE, Mendeleev communications, (3), 1994, pp. 81-82
The E,E-germacranolide hanphilline has been photochemically transforme
d into its Z,Z-isomer; and X-ray structural study has shown that the t
en-membered ring in this compound adopts the previously unknown 15D5,1
D14 boat-boat conformation.