Home – Home – Jornals – Chemistry for Sustainable Development 2026 number 5

Epoxidation reactions at the double bond in the aliphatic and cyclic moieties of triterpenoid and sterol molecules, followed by epoxide ring opening using sodium azide, and azide-alkyne cycloaddition reactions catalysed by copper salts offer a wide range of opportunities for the synthesis of new heterocyclic compounds. The synthetically understudied triterpene alcohols - butyrospermol 1 (the major component poplar bark triterpenols) and hop-20(21)-en-3β-ol 8 (a minor component, an isomer of moretenol) differing by double bond localisation in position 20,21 of the E ring were chosen as the starting substrates. Both compounds were isolated from black poplar (Populus nigra L.) bark, a large-scale product of the biomass processing of the Populus genus plants, which are among the main forest-forming and ornamental woody plants. The epoxides of butyrospermol at the double bonds in the aliphatic and cyclic parts of the molecule and the epoxides of hop-20(21)-en-3β-ol acetate at the E ring were synthesised for the first time. Azidoalcohols and 1,2,3-triazoles were obtained for the first time using butyrospermol acetate. Isomeric epoxy diols, formed by hydrolysis of the epoxide at the 24,25 double bond, were detected as byproducts. All starting and synthesised compounds were characterised using ¹³C and ¹H NMR spectroscopy.