ABEO-ABIETANE

Source Chamaecyparis pisifera Endl. Mol. formula C2QH p02 Mol. wt. 302 Solvent CDClo 

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Fig. (30). Leukotriene D4 antagonistic 19 (4- 3)-abeo-abietanes from Tripterigium wilfordii...

More than 20 quinoid 13,16-cycloabietanes, named as eoleones A-Z, oeeur in the yellow glands in the leaves of Afriean Coleus speeies (Labiatae). Lanugone A isolated from Plectranthus lanuginosis (Labiatae) represents a quinoid n(lS)-abeo-abietane. Totaranes sueh as (-l-)-totarol and the derived biphenyl-type dimer (-t)-podototarine are found in the wood of Podocarpus totara (Cupressaeeae). 

After the initial reports by Banerjee et al. on the intramolecular reductive Heck reaction in the synthesis of abeo-abietane-type diterpenoids, " Node et al. adopted the intramolecular asymmetric Heck reaction for the synthesis of (—)-dichroanal B, (—)-dichroanone, and taiwaniaquinone H. Palladium cyclization of triflate 18 using (/ )-Synphos as ligand and successive hydrogenation afforded the key intermediate (5)-19 in 86% yield and 94% ee. Significantly, both E/Z triflates of 18 gave the desired Heck product 19 indicating an equilibrium between the two isomers (Scheme 13.7). 

Node M, Ozeki M, Planas L, Nakano M, Takita H, Mori D, Tamatani S, Kajimoto T. Efficient asymmetric synthesis of abeo-abietane-type diterpenoids by using the intramolecular Heck reaction, i. Org. Chem. 2010 75(1) 190-196. 

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