78178-29-7Relevant academic research and scientific papers
Synthesis and structural analysis of sterically hindered chiral 1,4-diol ligands derived from the lignan hydroxymatairesinol
Brusentsev, Yury,Sandberg, Thomas,Hotokka, Matti,Sj?holm, Rainer,Eklund, Patrik
supporting information, p. 1112 - 1115 (2013/04/10)
The readily available natural lignan hydroxymatairesinol was transformed into sterically hindered and optically pure diphenyl, di-2-naphthyl, and tetramethyl 1,4-diol derivatives via arylation/alkylation of the aryltetralinbutyrolactone lignan (-)-conidendrin. In addition, the diastereoselective formation of stable hemiketals from the highly substituted butyrolactone was studied in detail. The conformations of the molecules prepared were studied computationally at molecular mechanics (MM), Hartree-Fock (HF)/6-31G*, and (DFT/B3LYP/TZVP) levels including entropy contributions and by NMR-spectroscopy. The conformations adopted showed that these novel chiral 1,4-diols may be suitable as chiral ligands for the development of new chiral transition metal and organo catalysts.
TWO CAFFEIC ACID TETRAMERS HAVING ENANTIOMERIC PHENYLDIHYDRONAPHTHALENE MOIETIES FROM MACROTOMIA EUCHROMA
Nishizawa, Makoto,Tsuda, Masashi,Hayashi, Koji
, p. 2645 - 2649 (2007/10/02)
Two caffeic acid tetramers were isolated from the dried root of Macrotomia euchroma, and the structures were established on the basis of spectral data and chemical conversion.These two compounds are shown to have enantiomeric 1,2-dihydro-1-(3',4'-dihydrox
Asymmetric Lignan Synthesis: Isolariciresinol Dimethyl Ether
Charlton, James L.,Alauddin, M. M.
, p. 3490 - 3493 (2007/10/02)
An asymmetric synthesis of the lignan (+)-isolariciresinol dimethyl ether 1 in nine steps and 13percent yield (83percent optical purity) from veratraldehyde is described.Veratraldehyde was converted to 6-(3,4-dimethoxybenzyl)veratraldehyde 3 by bromination, acetal formation, metalation, and coupling to 3,4-dimethoxybenzyl bromide. 3 was irradiated in the presence of SO2 to give the 3-hydroxy-1-aryl-1,3-dihydrobenzothiophene 2,2-dioxide 4, which was converted to the (R)-1-phenylethoxy derivative 5b. 5b on heating with dimethyl fumarate gave a mixture of primarily two diastereomeric cycloadducts 7b and 7b', both of which had the 1,2-trans, 2,3-trans , 3,4-cis stereochemistry.The major adduct 7b was subsequently assigned the stereochemistry 1S,2R,3S,4S.Separation and hydrogenolysis of the major adduct gave the diester 8, 1S,2R,3R, which was reduced with LiAlH4 to give (+)-isolariciresinol dimethyl ether 1.A racemic synthesis was also carried out via the methoxy sulfone 5a and its trans isomer 5a' in 33percent yield.
The Synthesis of Lignans and Related Structures using Quinodimethanes and Isobenzofurans: Approaches to the Podophyllins
Mann, John,Piper, Susan E.,Yeung, Lilan K.P.
, p. 2081 - 2088 (2007/10/02)
Novel routes to 1-aryl-5,6-dialkoxy-1,3-dihydrobenzothiophene 2,2-dioxides (13) and to the corresponding benzofuran (8) have been developed; these species yield quinodimethanes (12) via thermal extrusion of SO2 and isobenzofurans (5c) in an acid-cat
