Epoxidation of alnus-5-en-3β-yl acetate with m-chloroperbenzoic acid gave a 5β,6β-epoxide as a main product together with a 5α,6α-epoxide as a minor product. Treatment of the α-epoxide with BF3·OEt2 afforded a 1(10),5-diene and a mixture of 6α-hydroxy-12- and -18-ene derivatives. The 12-ene was converted into daturadiol (=olean-12-ene-3β,6β-diol).
Abstract Two new triterpenoids were isolated together with β-amyrin acetate, taraxeryl acetate, lupenyl acetate, 3β-acetoxy-30-norlupan-20-one, α-amyrenonol and sitosterol from the whole herb of Euphorbiamaculata. The structures of the new compounds were characterized as gult-5-en-3β-yl acetate and ursa-9(11):12-dien-3β-ol on the basis of chemical and spectral evidence.
chalcones, schefflerin and isoschefflerin, were isolated from the petrol fraction of the ethanol extract of the stem bark of Uvaria scheffieri , in addition to D: B-friedoolean-5-en-3β-ol (= glutin-5-en-3β-ol), 3-farnesylindole, 2′-hydroxy-3′,4′,6′-trimethoxychalcone, 2′,6′-dihydroxy-3′,4′-dimethoxychalcone, β-sitosterol and benzylbenzoate.
Contrary to the reported literature, the main epoxide derived from alnus-5-en-3β-yl acetate (1) was shown to be a β-epoxide. Daturadiol (=olean-12-ene-3β,6β-diol) was prepared from dendropanoxide via 1 and its α-epoxide.