Stereostructures and conformations of four diterpene lactones from Gelonium multiflorum1This paper is dedicated to our teacher Professor (Mrs.) Asima Chatterjee on the occasion of her 80th birth anniversary with profound regards and best wishes. Presented at the Sixth National Bioorganic Symposium, Indian Institute of Science, Bangalore, 5–7 June, 1997, Book of Abstracts, IP 3, and at the `National Symposium on Recent Developments in Natural Products', Andhra University, Visakhapatnam, 11–13 July, 1997, Abstracts, SL 11. Part 35 in the series `Terpenoids and Related Compounds'. For Part 34 see ref.[1]for Part 33 see ref.[2].1