The versatile conversion of lactams to the α-alkylated azacycles via cyclic N,O-acetal TMS ether
摘要:
The efficient preparation of the cyclic N,O-acetals from lactams by DIBAL reduction followed by direct trapping of the resulting N,O-hemiacetals using TMSOTf/pyridine system is described. In addition, the facile nucleophilic addition of various carbon nucleophiles at the carbonyl carbons of the lactams through the corresponding N,O-acetals is also reported. (C) 2002 Published by Elsevier Science Ltd.
The efficient preparation of the cyclic N,O-acetals from lactams by DIBAL reduction followed by direct trapping of the resulting N,O-hemiacetals using TMSOTf/pyridine system is described. In addition, the facile nucleophilic addition of various carbon nucleophiles at the carbonyl carbons of the lactams through the corresponding N,O-acetals is also reported. (C) 2002 Published by Elsevier Science Ltd.
A New Ring Expansion Reaction of 1-Acyl-2-vinylpiperidine and 1-Acyl-2-Vinylpiperazine via Aza-Claisen Rearrangement of Amide Enolate
Abstract A newringexpansionreaction of 1-acyl-2-vinylpiperidines and 1-acyl -2-vinylpiperazines has been achieved. Amide enolate induced aza-Claisen rearrangements of 1-acyl-2-azacycles provide the corresponding lactams possessing various substituents at α-position of carbonyl in good yields.