Fernene derivatives

Two new rearranged hopanes, alangidiol (178) and isoalangidiol (179), with a d-e cis fusion have been reported from the leaves of Alangium lamarckii. New fernene derivatives which have appeared this year include fern-9(l l)-en-6a-ol (180) and fern-9(ll)-en-20j8-ol (181) from the rhizomes of Polypodium juglandifolium and hortensol (182) from the leaves of Evodia hortensis The structure of (182) was confirmed by A"-ray analysis. 

Gonzalez, Martin, and Perez 148) identified three new fernene derivatives from Xanthoria resendei 12a-acetoxy-3p-hydroxyfern-9(ll)-ene (498), 3p,12a-dihydroxyfern-9(l l)-ene (499) and 3,12-diketofern-9(l 1)-ene (500). The structures of these triterpenes were deduced from spectral evidence and confirmed by chemical interconversion and the Wolff-Kishner reduction of (500) to the parent fern-9(ll)-ene. 

Also from Lobaria species were isolated the new fernene derivatives retigeric acid A (125) and retigeric acid B (Takahashi et aL 1972). 

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