Collect. Czech. Chem. Commun.
1986, 51, 621-635
https://doi.org/10.1135/cccc19860621
Preparation of C(18)-empiric 20,29,30-trinorlupane derivatives. 1H, 13C NMR and mass spectra
Václav Křečeka, Jiří Protivaa, Miloš Buděšínskýb, Eva Klinotováa and Alois Vystrčila
a Department of Organic Chemistry, Charles University, 128 40 Prague 2
b Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6
Abstract
Reaction of amide I with nitrous acid gave the olefins II, III and IV. On allylic oxidation of olefin IV α,β-unsaturated ketone V is formed from which olefins VIII and IX were prepared by a sequence of further reactions. Addition of hydrogen to the double bond of olefin IV and α,β-unsaturated ketone V takes place on catalytic hydrogenation from the β-side and leads to derivatives with cis-annellated rings D/E. This made the preparation of hydrocarbons VI and VII epimeric on C(18) possible, which represent reference compounds for the study of the effect of substituents on the chemical shifts of the methyl groups and the saturated carbon atoms of 18αH and 18βH-lupane derivatives. The configuration of the hydroxyl group in epimers XI and XII were derived from 1H NMR spectra. Deuteration of olefins III, IV and IX gave deuteriohydrocarbons XVI to XVIII. The 1H, 13C NMR and mass spectra of the substances prepared are discussed.
