Process Development of (1<i>S</i>,2<i>S</i>,5<i>R</i>,6<i>S</i>)- Spiro[bicyclo[3.1.0]hexane-2‘,5‘-dioxo-2,4‘-imidazolidine]-6-carboxylic Acid, (<i>R</i>)-α-Methylbenzenemethanamine Salt (LSN344309)
作者:Ossama M. Rasmy、Radhe K. Vaid、Michael J. Semo、Erik C. Chelius、Roger L. Robey、Charles A. Alt、Gary A. Rhodes、Jeffery T. Vicenzi
DOI:10.1021/op049829e
日期:2006.1.1
process for the synthesis of 4 and its resolution to obtain (1S,2S,5R,6S)-spiro[bicyclo[3.1.0]hexane-2‘,5‘-dioxo-2,4‘-imidazolidine]-6-carboxylic acid, (R)-α-methylbenzenemethanamine salt (5) are described. Starting from the inexpensive raw 2-cyclopenten-1-one and sulfur ylide 1 the racemic bicyclo keto ester 2 was synthesized. Reaction of 2 with potassium cyanide and ammonium carbonate under Bücherer−Berg's