Studies related to naturally occurring acetylene compounds. XXXIV. Some Australian members of the genus Cotula L

Seven Australian species of the genus Cotula L. have been investigated with particular regard to their content of acetylenic compounds. Six contained acetylenic compounds. There was no perceivable simple relationship between the acetylenic compounds isolated, over the whole of that portion of the genus so far examined, or within the subgenera. Two of the acetylenic compounds are new. C. bipinnata Thunb. contained the hydrocarbon pentadeca-2,8,10,14-tetraene-4,6-diyne (XX), and C. plumosa (Hook. f.) Hook. f., the alcohol 2-cis-heptadeca-2,8 10-triene-4,6-diyn-1-ol (XV), the cis isomer of oenanthetol. Acetylenes were not found in C. australis (Sieb. ex Spreng.) Hook. f., but methyl 4-isopantenoxycinnamate (XXII) was isolated from it in fair yield, and the new ester, 3,5-dimethoxy-l-α-propenylphenyl 4-isovalerate (XIX) was isolated from C. filicula (Hook. f.) Benth.