Photoinduced Electron Transfer (PET) Promoted Oxidative Activation of 1-(N-Benzyl-N-methylglycyl)-(S)-prolinol: Development of Novel Strategies Towards Enantioselective Syntheses of α-Amino Acids, Their N-Methyl Derivatives and α-Hydroxy Acids Employing (S)-Prolinol as aRecyclable Chiral Auxiliary

✍ Scribed by Ganesh Pandey; Parthasarathi Das; P. Yella Reddy

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 340 KB
• Volume: 2000
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(200002)2000:4<657::aid-ejoc657>3.0.co;2-6

✦ Synopsis

Photoinduced electron transfer (PET) / Enantioselective syntheses / α-Amino acids / α-Hydroxy acids / (S)-Prolinol / Recyclable chiral auxiliary PET activation of 1-(N-benzyl-N-methylglycyl)-(S)-prolinol (1) in dry acetonitrile, utilizing 1,4-dicyanonaphthalene (DCN) as a light-harvesting electron-acceptor and methyl viologen (MV ++ ) as an electron-transfer mediator, leads to the formation of 3-[benzyl(methyl)amino]perhydropyrrolo-[2,1-c][1,4]oxazin-4-one (3). When this photolysis is carried out in aqueous acetonitrile, exclusively 3-hydroxyperhydropyrrolo [2,1-c][1,4]oxazin-4-one (4) is produced. The formation of 3 can be rationalized in terms of intramolecular cyclization of the in situ generated iminium cation