21966-92-7Relevant academic research and scientific papers
Synthesis and applications of diphosphine ligands derived from the lignan hydroxymatairesinol
Brusentsev, Yury,Eklund, Patrik
, p. 260 - 263 (2015/03/14)
Highly efficient methods for synthetic modifications of the natural lignan hydroxymatairesinol into chiral diphosphines similar to DIOP were developed. Catalytic activity and induction of enantioselectivity for the prepared phosphines were evaluated in rh
Cytotoxic responses to aromatic ring and configurational variations in α-conidendrin, podophyllotoxin, and sikkimotoxin derivatives
Dantzig,LaLonde,Ramdayal,Shepard,Yanai,Zhang
, p. 180 - 185 (2007/10/03)
Derivatives of α-conidendrin, podophyllotoxin, and sikkimotoxin were prepared to evaluate the cytotoxic contributions of C-4 configuration and pendant and fused arene substitutions. Dimethyl-α-conidendryl alcohol (5), 9-deoxypodophyllol (6), and 9-deoxysikkimol (17) were dehydrated to their respective oxolane derivatives 4, 3, and 9. Diols 5 and 6 were converted via oxabicyclo[3.2.1]octanols 10 and 14 to target oxolanes 8 and 7 where C-4 had been inverted relative to that in 3 and 4. Cytotoxicities of the five oxolanes were determined in two drug-sensitive human leukemia and two multidrug-resistant cell lines expressing P-glycoprotein or multidrug-resistance associated protein (MRP). Changing the pendant arene configuration or replacing a m-methoxy by hydrogen resulted in a 100-fold cytotoxicity loss. Replacing a methylenedioxy group in the fused arene by two methoxy substituents reduced cytotoxicity by 10-fold. Drug-resistant cell lines were equally resistant to compounds 3, 4, 8, and 9 indicating that these four compounds do not serve as substrates of the transport proteins P-glycoprotein and MRP.
Synthetic experiments in lignans Part XV - Reductive rearrangements of 2,6-diaryl-3,7-dioxabicycloocatne lignans with AlCl3 and (C2H5)3SiH
Anjaneyulu, A. S. R.,Kumar, D. S.,Venkateswarlu, R.,Kamakshi, C.
, p. 897 - 899 (2007/10/03)
The mixture of AlCl3 and (C2H5)3SiH has been found to cleave the benzyl ethers of the lignans, gmelinol, paulownin, wodeshiol and eudesmin leading to a tetrahydrofuran, a tetrahdyropyran or an aryltetralin derivative by reductive rearrangement.
LIGNANES.10. PREPARATION DES (R)-(+) ET (S)-(-)-β-PIPERONYL ET β-VERATRYL-γ-BUTYROLACTONES ET LEUR UTILISATION DANS LA SYNTHESE TOTALE DE LIGNANES OPTIQUEMENT ACTIFS
Brown, Eric,Daugan, Alain
, p. 141 - 154 (2007/10/02)
A simple and efficient route leading to optically active β-benzyl-γ-butyrolactones is described.Thus, the methyl (R,S)-α-benzylhemisuccinate resulting from a Stobbe condensation with an appropriate aromatic aldehyde, followed by catalytic hydrogenation of the intermediate α-benzylidene hemisuccinic ester, was resolved by means of a chiral base (ephedrine or α-methyl benzylamine).Reduction of each enantiomer, using calcium borohydride, then led to the corresponding optically active β-benzyl-γ-butyrolactone.In this way, the following two lactones were obtained in both (R)-(+) and (S)-(-) enantiomeric forms, β-piperonyl- and β-veratryl-γ-butyrolactones 1 and 2 respectively.These lactones were used as key-intermediates for the syntheses of 17 optically active lignans and lignoids, such as (-)-dimethylmatairesinol (-)-23, (-)-kusunokinin (-)-26 and (+)-dimethylisolariciresinol (+)-35.
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.
(R)-(+)-β-VERATRYL-γ-BUTYROLACTONE, A NEW KEY-INTERMEDIATE FOR THE ASYMMETRIC SYNTHESIS OF VARIOUS LIGNANS
Brown, Eric,Daugan, Alain
, p. 3719 - 3722 (2007/10/02)
Methyl α-veratrylhemisuccinate was resolved into its (R)-(+) and (S)-(-) antipodes by (S)-(-) and (R)-(+)-α-methylbenzylamine respectively.Calcium borohydride reduction of the (R)-(+)-hemiester afforded (R)-(+)-β-veratryl-γ-butyrolactone.The latter was us
