Thuc Dinh Ngoc*, Wim Dehaen, Luc Van Meervelt and Jan Balzarini Pages 2969 - 2974 ( 6 )
Grignard reactions were applied to synthesize 2-ethynyl-2-hydroxylallobetulin 5 from 2-oxoallobetulin 4. The compound plays an important role as starting material to synthesize heterocyclic triterpenes using the click reaction. A series of new 1,2,3-triazole derivatives derived from 2-oxoallobetulin were successfully obtained. Under similar reaction conditions, only one compound 6 kept the hydroxyl functional group, while in the other compounds 7, 8 and 9, water was eliminated. The structures of obtained compounds were confirmed by 2D-NMR spectroscopy. The X-ray analysis of 5 indicated that only one isomer was obtained and in this compound, the hydroxyl group is situated on the same side as the ether group, the ethynyl group being situated at the opposite side. All products were also evaluated for their cytostatic activity in cell culture including L1210, CEM and Hela. Several compounds showed measurable cytostatic activity in the micromolar range.
Grignard reactions, click reaction, 2-oxoallobetulin, 1, 2, 3-triazole, lymphoblast CEM tumor cells, cervix carcinoma HeLa, murine leukemia.
Department of Science and Technology Management, Hong Duc University, Thanh Hoa, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, 3001 Leuven, Rega Institute for Medical Research, KU Leuven, 3000 Leuven