title: New synthesis of (S)-dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethenedioxy-biphenyl-2,2'-dicarboxylate by configuration transform.
abstract: (R/S)-4,4'-Dimethoxy-5,6,5',6'-dimethenedioxy-2,2'-di-(4(S)-methyl-oxazoline-1)-biphenyl has been synthesized from dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethenedioxy-biphenyl-2,2'-dicarboxylate, and then the diastereoisomer mixture was almost fully converted to a single diastereoisomer with S-configuration ((S)-3) through the key configuration transform promoted by CuI, which was confirmed by CD, HPLC and (13)C NMR. The C(2)-symmetric biphenyl, (S)-dimethyl-4,4'-dimethoxy-5,6,5',6'-dimethenedioxy-biphenyl-2,2'-dicarboxylate was prepared easily via the hydrolysis and ester exchange of (S)-3.
authors.affiliation: Center of Research, Henan Academy of Science, Zhengzhou, Henan 450002, China.
authors.forename: Sen-Xiang
authors.initials: SX
authors.lastname: Cheng
authors.forename: Jun-Biao
authors.initials: JB
authors.lastname: Chang
authors.forename: Ling-Bo
authors.initials: LB
authors.lastname: Qu
authors.forename: Rong-Feng
authors.initials: RF
authors.lastname: Chen
mesh_terms: D001713:Biphenyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D034242:Cyclooctanes / Q000138:chemical synthesis / Q000737:chemistry; D003998:Dicarboxylic Acids / Q000138:chemical synthesis* / Q000737:chemistry; D017705:Lignans / Q000138:chemical synthesis / Q000737:chemistry; D008968:Molecular Conformation; D011083:Polycyclic Compounds / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D001713:Biphenyl Compounds; D034242:Cyclooctanes; D003998:Dicarboxylic Acids; D017705:Lignans; D011083:Polycyclic Compounds; C434677:dimethoxy biphenyl monocarboxylate; C031409:schizandrin C