New type of azacyclization: thermal preparation of 4,6-disubstituted 2-piperidinone from N-sulfonyldienamide and its substituent effect
2012
Abstract The thermal 6-endo cyclization of N -sulfonyl-2,4-dienamide compounds to produce 4,6-disubstituted 2-piperidinone is described. The observed remarkable substituent effect due to the N -sulfonyl and C3 ethoxycarbonyl groups for acceleration of this 6-endo cyclization strongly suggests that the reaction would proceed via the 6π-azaelectrocyclization of the intermediary imidic acid. On the contrary, the corresponding 5-formyl and 5-acetyl derivatives rapidly cyclized at room temperature to produce the 5-exo cyclized products.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
38
References
15
Citations
NaN
KQI