The Formation and the Nucleophilic Substitution of 5-Acetoxy-5-chlorovaleronitrile

Use of Cyclopentadiene IV

Abstract

The Beckmann fission of 2-acetoxycyclopentanone oxime (1e) and 2-benzoyloxycyclopentanone oxime (1f) with phosphorus pentachloride at 0°C gave5-acetoxy-5-chlorovaleronitrile (3e) and 5-benzoyloxy-5-chlorovaleronitrile (3f) in 56 %and 71 % yields, respectively. The hydrolysis of (3e) gave 4-cyanobutanal (2) and 5-acetoxy-cis-4-pentenenitrile (5). The methanolysis of (3e) gave (2) and its dimethyl acetal (6). These reactions proceeded by the Sn1 mechanism. The reaction of (3e) with several nucleophiles were carried out in anhydrous and aqueous solvents. Sodium cyanide and silver nitrite reacted with (3e) in anhydrous tetrahydrofuran or diethyl ether to give 2- acetoxyadiponitrile (7) (99 ro) and 1-acetoxy-4-cyanobutyl nitrite (9) (59 %), respectively. Sodium azide and sodium acetate hardly reacted with the chlorine of (3e) in anhydrous acetone, whereas 5-acetoxy-5-azidovaleronitrile (10) and 5, 5-diacetoxyvaleronitrile (11) were obtained in about 20 % yield in aqueous acetone.