Triterpenes from the leaves ofBetula ermanii

Summary From the unsaponifiable fraction of an ethereal extract of the leaves ofBetula ermanii a new triterpene of the dammarane series — 20,24-epoxydammarane-3,6,25-trol (II) — and its 6-O-acetyl derivative (I) have been isolated.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center of the Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 587–590, September–October, 1978.