Method for Improving Optical Purity of 2-Hydroxycarboxylic Acid or Derivative Thereof
申请人:KOWA COMPANY, LTD.
公开号:US20160060203A1
公开(公告)日:2016-03-03
To provide a method for improving optical purity of an optically active 2-hydroxycarboxylic acid or a derivative thereof, which is useful as a raw material in the manufacture of medicines, agrochemicais, and industrial products. The method of the invention for improving purity of a hydroxycarboxylic acid of the following formula (1a) or (1b) or a derivative thereof includes the steps of reacting the hydroxycarboxylic acid of the following formula (1a) or (1b) with at least one optically inactive base selected from the group consisting of an alkali metal, alkoxide and a secondary amine in the presence of a solvent and, subsequently, performing recrystallization, to thereby form a hydroxycarboxylic acid salt of the following formula (IIIa) or (IIIb):
wherein R
1
represents a C
1-8
alkyl group, and R
2
represents an alkali metal or a secondary amine.
Converting a Birch Reduction Product into a Polyketide: Application to the Synthesis of a C<sup>1</sup>-C<sup>11</sup>Building Block of Rimocidin
作者:Luc Nachbauer、Reinhard Brückner
DOI:10.1002/ejoc.201201112
日期:2012.12
A stereoselective synthesis of a C1–C11 building block for the polyol-polyene antibiotic rimocidin has been developed. Its functional groups originate from a disubstituted indane, which underwent Birchreduction, and oxidative cleavage. This provided a dihydropyranone with a β-keto ester side-chain. The latter was subjected to a Noyori hydrogenation (ds > 97:3). An oxy-Michael addition gave a mixture
A practical synthesis of optically pure PPARα agonist, (R)-K-13675, is described. This process is based on the use of (S)-2-hydroxybutyrolactone, which can be transformed into the requisite n-butyl (S)-2-hydroxybutanoate in an efficient manner. A key reaction is the etherification between the phenol and n-butyl (S)-2-trifluoromethanesulfonyloxybutanoate to give the phenyl ether in excellent yield without
OPTICALLY ACTIVE PPAR-ACTIVATING COMPOUND INTERMEDIATE AND METHOD FOR PRODUCING SAME
申请人:Yamazaki Yukiyoshi
公开号:US20090023944A1
公开(公告)日:2009-01-22
The present invention provides a production intermediate for compound (A-1) and a method for producing the intermediate at high yield and high optical yield.
The present invention provides a method for producing compound (3) characterized in that compound (1) is reacted with compound (2) in the presence of a base.
(wherein R represents a C1 to C6 alkyl group or a C7 to C8 aralkyl group).
A process for producing an optically active 2-hydroxybutyric ester (1), characterized by including reacting an optically active 2,3-epoxybutyric ester (2) with a thiol in the presence of scandium trifluoromethanesulfonate or ytterbium trifluoromethanesulfonate, to thereby produce Compound (3), and subjecting Compound (3) to desulfurization reaction:
(wherein R represents a C1 to C6 alkyl group or a C7 or C8 aralkyl group; R
1
represents a C1 to C12 alkyl group or a phenyl group; and * represents S- or R-absolute configuration).
The present invention provides a process for producing an optically active 2-hydroxybutyric ester at high yield and high optical purity.