Abstract
The usefulness of “quantitative conformational analysis” of some terpenes and steroids was demonstrated. Detection of stable conformers which were often not found in crystalline state enabled to determine the configuration of compound 9, to assign the absolute configuration of dilophol (2), to analyse dynamic NMR of caryophyllene (4), and to suggest biosynthetic routes for cyclohumulanoids from humulene (5). Estimation of barrier of internal rotation around C (17) -C (20) bond of steroid gave a solution to a long lasting dispute. Ring inversion barrier of germacrene B (7) was estimated to give valuable data for argument about isolation of optically active germacrenes without a chiral atom. The course of some transannular reactions was explained by strain energy of possible products.
