71298-20-9Relevant articles and documents
Structures of Four New Oxygenated Lupanes from Pleurostylia opposita (Celastraceae)
Dantanarayana, Anura P.,Kumar, N. Savitri,Sultanbawa, M. Uvais S.,Balasubramaniam, Sinnathamby
, p. 2717 - 2723 (2007/10/02)
Four new oxygenated lupanes isolated from the steam bark of Pleurostylia opposita (Wall) Alston (Celastraceae) have been shown to be lupa-5,20(29)-dien-3-one (2), 6β,20-dihydroxylupan-3-one (5), 3β,6β-dihydroxylup-20(29)-ene (6), and 6β,28-dihydroxylup-20(29)-en-3-one (8).The structures of these compounds were established on the basis of spectroscopic (1H n.m.r. and mass spectra) and chemical evidence.Deshielding of three methyl signals in the 1H n.m.r. spectra of 6β-hydroxylupane derivatives has been attributed to 1,3-diaxial interaction between the relevant methyl group and the 6β-hydroxy-group.