2005

200517.fm Page 222 Friday, March 18, 2005 2:52 PM

Nucleic acidsU 0700 Controlling Stereochemistry During Oxidative Coupling. Preparation of Rp or Sp

Phosphoramidates from One P-Chiral Precursor. — The direct oxidative coupling of (Sp)-(I) via the corresponding phosphoroiodidate proceeds with inversion of config-uration. In contrast, treatment of iodidate with chloride proceeds with an additionalinversion of configuration and thus the phosphoramidate (Sp)-(IV) is produced with net retention of configuration. — (NILSSON, J.; STAWINSKI*, J.; Chem. Commun. (Cambridge) 2004, 22, 2566-2567; Dep. Org. Chem., Arrhenius Lab., Univ. Stockholm, S-106 91 Stockholm, Swed.; Eng.) — M. Paetzel

17- 202