Diastereoselective Michael Additions of Chiral Imidazolidines to Trityl Enones
The enolates A and C of t-butyl (R)-2-t-butyl-3-methyl-4-oxo-1-imidazolidinecarboxylate (1, Boc-BMI) and of 1-t-butyl 5-methyl (2R,5S)-2-t-butyl3-methyl-1,5-imidazolidinedicarboxylate (3) and t-butyl (R)-2-t-butyl-5-lithio-3-methyl-1-imidazolidinecarboxyl