After a preliminary investigation of the chemistry of western white pine bark (l), a more detailed study of the benzene extract was undertaken.
A total of 90 terpenoids were isolated, including 34 triter-penes (2). These include 24-methylenecycloartano1, 10 known and 10 new serratanes (3) and 11 new triter-penes that appear to have a common skeleton. The two major components of this last group are a awthoxydiol (I) and a trio1 (IV) which comprise 0.7 and 0.2% of the benzene extract, respectively. This communication describes the proof of structure of these two novel and biogenetically interesting triterpenes. The unsaponifiable portion from the benzene extract was freed of wax alcohols by formation of the urea canal inclusion complex and of sterols by precipitation of the digitonides. The petroleum ether-insoluble fraction was chromatographed on silica gel to yield the novel triterpenes. The methoxydiol. C3IH5403, (m/e 474.409 (4)). m.p. 193-194". [o]i2 + 77" exhibited in the NMR spectrum. tertiary methyl groups at 60.66, 0.74, 0.80. 0.97, 1.05, 1.09 and 1.25; a secondary methyl at 0.90 (d, J96 Hz), an equatorial secondary methoxyl (3.36, s, OCIl3 and 2.65, m, CgOCH3) a multiplet at 3.62 for CEOH and a single olefinic proton at 5.25 (m). It readily formed a monoacetate (II) * To whom enquiries should be addressed ** Wisconsin Section of the American Chemical Society postdoctoral fellow.