75683-62-4Relevant articles and documents
Synthetic approach to exo-endo cross-conjugated cyclohexadienones and its application to the syntheses of dehydrobrachylaenolide, isodehydrochamaecynone, and trans-isodehydrochamaecynone
Higuchi, Yohsuke,Shimoma, Fumito,Koyanagi, Rei,Suda, Kouji,Mitsui, Tomokazu,Kataoka, Takao,Nagai, Kazuo,Ando, Masayoshi
, p. 588 - 594 (2003)
Methodology for synthesis of exo-endo cross-conjugated dienones with trans- and cis-decalin systems has been reported. Bromination of the silyl enol ether of α′-methyl α,β-unsaturated ketones with PTAB and successive dehydrobromination of the resulting α′-bromo-α′-methyl α,β-unsaturated ketones under three conditions (DBU/PhH; TBAF/THF; Li2CO3, LiBr/DMF) gave the desired exo-endo cross-conjugated dienones in good yield. This method was applied to the syntheses of dehydrobrachylaenolide (1), isodehydro-chamaecynone (5c), and trans-isodehydrochamaecynone (11) starting from tuberiferine (7), chamaecynone (5a), and trans-chamaecynone (9). Eudesmanolides possessing an α-methylene γ-lactone moiety, i.e., 1, 7, and 13, exhibited significant inhibitory activity toward the induction of the intercellular adhesion molecule-1 (ICAM-1). Compound 1 showed greater activity than 7 and 13. All compounds possessing an ethynyl group, 5d, 9, 11, and 14, showed the same degree of termiticidal activity, and the exo-endo cross-conjugated dienone structure in 11 had no influence on the activity.
