212912-54-4Relevant articles and documents
Highly efficient asymmetric access to 1-azaspiro[4.4]nonane skeleton
Planas, Lo?c,Pérard-Viret, Jo?lle,Royer, Jacques,Selkti, Mohamed,Thomas, Alain
, p. 1629 - 1632 (2007/10/03)
Vinylogous Mukaiyama aldol type reaction of chiral non-racemic silyloxypyrroles followed by acidic treatment affords an efficient asymmetric access to 1-azaspiro[4.4]nonanes in high diastereoisomeric excess (up to 79%).
A new asymmetric approach towards 2-pyrrolidinones and pyrrolidines: Simple versus double stereodifferentiation
Poli, Giovanni,Ciofi, Simone,Maccagni, Elisa,Sardone, Nicola
, p. 8669 - 8672 (2007/10/02)
The condensation of a chiral 2-silyloxypyrrole derivative with achiral and chiral formyl cation equivalents has been studied for the first time. The methodology allows to build-up pyroglutammic aldehydes and prolinal systems with a stereocontrol from good to excellent. Whereas the chiral auxiliary residing on the pyrrole system shows an intrinsic good level of diastereoface discrimination at C-5, the combined use of a 2-methoxy-3-tosyl-oxazolidine as a chiral formylating agent allows a total stereocontrol of the condensation. A rationale for the observed stereochemical outcome is presented.