33514-22-6Relevant articles and documents
"Cofactor"-controlled enantioselective catalysis
Dydio, Pawel,Rubay, Christophe,Gadzikwa, Tendai,Lutz, Martin,Reek, Joost N. H.
supporting information; experimental part, p. 17176 - 17179 (2011/12/13)
We report an achiral bisphosphine rhodium complex equipped with a binding site for the recognition of chiral anion guests. Upon binding small chiral guests-cofactors-the rhodium complex becomes chiral and can thus be used for asymmetric catalysis. Screening of a library of cofactors revealed that the best cofactors lead to hydrogenation catalysts that form the products with high enantioselectivity (ee?s up to 99%). Interestingly, a competition experiment shows that even in a mixture of 12 cofactors high ee is obtained, indicating that the complex based on the best cofactor dominates the catalysis.
Sesterterpenoids from the sponge Sarcotragus sp.
Wang, Nan,Song, Jueun,Kyoung, Hwa Jang,Lee, Hyi-Seung,Li, Xian,Oh, Ki-Bong,Shin, Jongheon
, p. 551 - 557 (2008/12/23)
Nineteen new sesterterpenoids and eight known compounds were isolated from the sponge Sarcotragus sp. collected from Soheuksan Island, Korea. The structures of these compounds were determined to be linear sesterterpenoids containing furan or related oxygenated functionalities on the basis of combined chemical and spectroscopic analyses. In addition, the configurations of several previously undetermined compounds were assigned. Several compounds exhibited moderate to major antibacterial activity (compounds 1-3, 17, 18) and cytotoxicity (3, 11, 12) against the K562 cell line and inhibitory activity against isocitrate lyase (6, 13).
Terpenoid Chemistry. XXIV (1R)-1-Methoxymyodesert-3-ene, an Iridoid Constituent of Myoporum deserti (Myoporaceae)
Grant, Hamish G.,O'Regan, Peter J.,Park, Robert J.,Sutherland, Maurice D.
, p. 853 - 878 (2007/10/02)
A common variety of Myoporum deserti A.Cunn. (Ellangowan Poison Bush) yields an essential oil consisting largely of the iridoid monoterpene, (1R)-1-methoxymyodesert-3-ene, C11H18O2, (1R,4aS,7R,7aR)-1-methoxy-4,7-dimethyl-1,4a,5,6,7,7a-hexahydrocyclopentapyran, b.p. 67 deg/2 mm, D - 165 deg.This cyclic acetal is hydrolysed to methanol and a mixture of two epimeric cyclopentanoid dialdehydes which are oxidized to the two epimeric trans, trans-nepetalinic acids and yield (+)-(R)-actinidine with Brady's reagent, (1R)-1-Methoxymyodesert-3-ene is oxidized by ozone/hydrogen peroxide to (1R,2R,5R)-2-acetyl-5-methylcyclopentanecarboxylic acid.Hydrogenation yields mainly (1R)-methoxymyodesertan, hydrolysed by aqueous maleic acid at room temperature to methanol and a cyclic hemiacetal, (1R,4R,4aR,7R,7aR)-4,7-dimethyl-1,3,4,4a,5,6,7,7a-octahydrocyclopentapyran-1-ol.Oxidation of this cis,cis-hemiacetal by bromine in acetate buffer yields a lactone further oxidized by chromic acid to (2R,1',S',2'R,3'R)-2-(2'-carboxy-3'-methylcyclopentyl)-propionic acid. (1R)-1-Methoxymyodesertan, refluxed with aqueous phthalic acid, yields (+)-(4R,4aR,7R)-4,7-dimethyl-3,4,4a,5,6,7-hexahydrocyclopentapyran.Treatment of the hexahydropentapyran, the cis,cis-hemiacetal or (1R)-1-methoxymyodesertan with hydrochloric acid yields a trans,trans-hemiacetal, (1R,4R,4aR,7R,7aS)-4,7-dimethyl-1,3,4,4a,5,6,7,7a-octahydrocyclopentapyran-1-ol,which equilibrates in solution to a mixture of α- and β-anomers.Spectral studies of these and other products establish the configuration of the natural product at C1. (1R)-1-Methoxymyodesert-3-ene is not toxic to sheep as are the β-substituted furans characteristic of most other chemovarieties of M. deserti.
