Synthesis of 2,5-disubstituted 3-(phenylsulfonyl)pyrrolidines via 5-endo-trig cyclisation reactions

Article abstract of DOI:10.1055/s-1997-1054

Reaction of lithiated (phenylsulfonyl)methane with enantiomerically pure N-diphenylphosphinylaziridines gives adducts 4, which may be acylated at the sulfone α-position by further lithiation and reaction with non-enolisable acid chlorides, giving ketones 5. Reduction followed by acetylation gives substrates 6, which undergo elimination and 5-endo-trig cyclisation to give 2,5-disubstituted 3-(phenylsulfonyl)pyrrolidines 7 in high yields and with excellent stereoselectivities. Some further reactions of the pyrrolidines are described.