Stereochemistry of the Intramolecular Substitution of Phenylselenonyl Group by Nitrogen Atom in Amide. Inversion of Configuration
作者:Akio Toshimitsu、Hidekiyo Fuji
DOI:10.1246/cl.1992.2017
日期:1992.10
The stereochemistry of the intramolecular substitution of phenylselenonyl group by a nitrogen atom in tosylamino group was proved to be inversion by the oxidative cyclization of (S)-1-alkyl-4-(tosylamino)butyl phenyl selenides to (R)-N-tosyl-2-alkylpyrrolidines.
An efficient procedure for the preparation of homochiral (R)-(+)-γ-decalactone 4 based on castor oil ozonolysis is described. The key intermediate, (R)-(−)-1,3-nonandiol 1, was transformed into monotosylate 2 and then reacted with sodium cyanide to give 3. Treatment of the latter with a dilute hydrochloric acid provided the enantiomerically pure lactone 4.
result in an intramolecularcyclization to chiral γ-lactones, which have a variety of biological uses. Starting with an assortment of different aldehydes (alkyl and aryl) a 4-step synthesis of γ-keto nitriles was developed. These prochiral substrates were then screened against a library of ketoreductases for their ability to stereoselectively reduce the carbonyl. Enzymes from the short chain dehydrogenase