Aza-[3,3]-Claisen enolate rearrangement in vinylaziridines: stereoselective synthesis of mono-, di-, and trisubstituted seven-membered lactams.
Several 2,3-disubstituted vinylaziridines have been N-acylated and subjected to LiHMDS in THF at -78 degrees C. Upon warming to room temperature, the resulting amide enolates underwent a highly stereoselective [3,3]-sigmatropic rearrangement to give mono-, di-, and trisubstituted seven-membered lactams in good yields. The scope and limitations of the process have been investigated by using variously substituted vinylaziridines. A kinetically controlled process proceeding through a six-membered boatlike transition state assembly has been invoked to explain the stereochemical outcome of the reaction.
Lindström
U M
UM
Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, Sweden.
Somfai
P
P
D001388:Aziridines / Q000737:chemistry*; D015195:Drug Design; D007700:Kinetics; D007769:Lactams / Q000138:chemical synthesis* / Q000737:chemistry; D008968:Molecular Conformation; D015394:Molecular Structure; D013237:Stereoisomerism
D001388:Aziridines; D007769:Lactams