| 摘要 |
1,204,923. Cyclopentylpropionic acid derivatives. ROUSSEL-UCLAF. 23 Aug., 1967 [25 Aug., 1966; 25 Nov., 1966; 7 July, 1967], No. 8259/70. Divided out of 1,204,921. Heading C2C. The invention comprises compounds of the following formulµ, those of Formulµ IV IVa and V being racemic and those of formulµ Va, Vb and VI being optically active, and the salts of compounds of formulµ Va and Vb with optically active bases wherein R is C 1-3 alkyl, R<SP>1</SP> is C 1-6 alkyl, R<SP>2</SP> is optionally substituted C 2-4 alkylene and R<SP>3</SP> is C 2-3 alkyl. Their preparations are as follows: IIIb by reacting an alkyl acrylate with a 2- alkyl-cyclopentane-1,3-dione; IV by ketalizing IIIb or the analogue thereof wherein R<SP>3</SP> is Me; IIIc by reacting acrylonitrile with a 2-alkylcyclopentane-1,3-dione; IVa by ketalizing IIIc or the analogue thereof wherein R<SP>3</SP> is Me; V by hydrolysis of IV or IVa, or by hydrolysis of Va or Vb to a 3-(1-alkyl-2,5-dioxocyclopentyl)-propionic acid and reketalization of the latter; Va and Vb by resolution of V with an optically active base; and VI by lactonization of Va or Vb. |
