126060-70-6Relevant articles and documents
Sc(OTf)3-catalyzed diastereoselective Friedel-Crafts reactions of arenes and hetarenes with 3-phenylglycidates
Wilcke, David,Bach, Thorsten
supporting information; experimental part, p. 6498 - 6503 (2012/09/08)
Five different para-substituted 3-phenylglycidates (3-phenyloxirane-2- carboxylates) were prepared and subjected to reactions with arenes and hetarenes under Lewis acid catalysis. Sc(OTf)3 was found to effectively (5 mol%) promote a Friedel-Crafts reaction in nitromethane as the solvent. The reaction was shown to proceed stereoconvergently, which makes the intermediacy of a benzylic cation likely. The diastereoselectivities varied depending on the choice of the nucleophile and 3-arylglycidate. Best results were obtained with tert-butyl 3-anisylglycidate, which delivered the respective products with high syn-preference in diastereomeric ratios (d.r.) between 82:18 and >95:5. The observed selectivity can be explained by a model, according to which the intermediate benzylic cations adopt a preferred conformation, which allows for diastereoface-differentiation by the adjacent stereogenic center.
Synthesis of taxoids II. Synthesis and antitumor activity of water-soluble taxoids
Harada, Naoyuki,Ozaki, Kunihiko,Yamaguchi, Tetsuo,Arakawa, Hiroaki,Ando, Akira,Oda, Kouji,Nakanishi, Noriyuki,Ohashi, Motoaki,Hashiyama, Tomiki,Tsujihara, Kenji
, p. 241 - 258 (2007/10/03)
Synthesis of novel taxoid water-soluble prodrugs that have 2′-substituted amino acid derivatives with spacer is described. Enantioselective synthesis of the C-13 side chains proceeded through the asymmetric dihydroxylation. Several compounds had good solubility in saline and showed potent antitumor activity against B16 melanoma in mice.
Reactions of Methyl threo-2-Acetoxy-3-chloro-3-(4-methoxyphenyl)propanoate and Methyl cis-2,3-Epoxy-3-(4-methoxyphenyl)propanoate with 3,5-Dimethoxyphenol: Potential Routes to Flavan-3-ols
Brown, Roger. F. C.,Jackson, W. Roy,McCarthy, Tom D.,Fallon, Gary D.
, p. 1833 - 1843 (2007/10/02)
Attempted syntheses of flavan-3-ols by reaction of either methyl threo-2-acetoxy-3-chloro-3-(4-methoxyphenyl)propanoate (3) or methyl cis-2,3-epoxy-3-(4-methoxyphenyl)propanoate (14) with 3,5-dimethoxyphenol failed to give the required aryl ethers.Products usually were derived from C-alkylation of the electron-rich phenol although reaction of the chloro acetate (3) with the phenoxide ion gave the furanone (5).The single-crystal X-ray structures of methyl 4-hydroxy-3-(4-methoxyphenyl)-2-(4-methoxyphenylmethyl)-5-oxo-2,5-dihydrofuran-2-carboxylate and cis-3-hydroxy-5,7-dimethoxy-4-(4-methoxyphenyl)-3,4-dihydro-2H-1-benzopyran-2-one have been determined.