Facile Synthesis of (R)-4-Mercaptopyrrolidine-2-thione from L-Aspartic Acid
作者:Masahiko SEKI、Toshiaki SHIMIZU
DOI:10.1271/bbb.65.973
日期:2001.1
prepared from L-aspartic acid, with potassium thiobenzoate provided (R)-benzoylthio derivative 5 with complete inversion of the configuration. Compound 5 was converted, via iodide 6c, to (R)-4-amino-3-benzoylthiobutyric acid 8b. (R)-4-Mercapto pyrrolidine-2-thione 1 was readily obtained from 8b through cyclization with acetic anhydride, thionation with Lawesson's reagent and facile removal of the S-benzoyl
Practical Synthesis of (<i>R</i>)-4-Mercaptopyrrolidine-2-thione from <scp>l</scp>-Aspartic Acid. Preparation of a Novel Orally Active 1-β-Methylcarbapenem, TA-949
作者:Masahiko Seki、Takeshi Yamanaka、Kazuhiko Kondo
DOI:10.1021/jo991461+
日期:2000.1.1
High-yield amination and cyclization of the chloride 15 to the pyrrolidin-2-one 16 was accomplished by a simple treatment with ammonia. Thiation of 16 and the Birch reduction of the resultant thiolactam 18 provided the C-2 sidechain 2 in high yield with the asymmetric center retained as such. The sidechain 2 was installed into the 1-beta-methylcarbapenem skeleton either by coupling with the vinyl phosphate