A convenient stereoselective access to new bis-phosphorylated pyrrolidinesand their corresponding nitroxides

Addition of one equivalent of dialkylphosphite to gamma -diketones yielded new 5-phosphorylated 1-pyrrolines 3. Depending on the experimental conditio ns, the addition of a second equivalent of dialkylphosphite to 3, led eithe r to (+/-)-2,5-bis-phosphorylated pyrrolidines 4 or a mixture of (+/-)- and meso-4. Pyrrolidines 4 were isolated and subsequently oxidized to the corr esponding stable (+/-)- or meso-nitroxides, 5. Coupling of (+/-)-5a with th e prochiral 2-phenyl-ethyl radical was investigated. (C) 2001 Academie des sciences / Editions scientifiques et medicales Elsevier SAS.