Application of Vicarious Nucleophilic Substitution to the Total Synthesis of dl-Physostigmine
摘要:
A concise, highly efficient formal total synthesis of dl-physostigmine is described, using a relatively simple method that should be adaptable to the synthesis of homologous members of this type of alkaloid. The key step in the synthesis is a new vicarious nucleophilic substitution reaction between p-nitroanisole and a C-silylated derivative of N-methylpyrrolidinone. Subsequent conversion of the initial adduct to the tricyclic framework of physostigmine follows a well-established protocol and provides the key intermediate 8 in high yield. The vicarious nucleophilic substitution reaction has also been extended to six-membered lactams, with encouraging results.
Kramarova, E. P.; Anisomova, N. A.; Baukov, Yu. I., Journal of general chemistry of the USSR, 1991, vol. 61, # 6.2, p. 1284 - 1290
作者:Kramarova, E. P.、Anisomova, N. A.、Baukov, Yu. I.
DOI:——
日期:——
Application of Vicarious Nucleophilic Substitution to the Total Synthesis of <i>dl</i>-Physostigmine
作者:Pankaj D. Rege、Francis Johnson
DOI:10.1021/jo026438u
日期:2003.8.1
A concise, highly efficient formal total synthesis of dl-physostigmine is described, using a relatively simple method that should be adaptable to the synthesis of homologous members of this type of alkaloid. The key step in the synthesis is a new vicarious nucleophilic substitution reaction between p-nitroanisole and a C-silylated derivative of N-methylpyrrolidinone. Subsequent conversion of the initial adduct to the tricyclic framework of physostigmine follows a well-established protocol and provides the key intermediate 8 in high yield. The vicarious nucleophilic substitution reaction has also been extended to six-membered lactams, with encouraging results.
Synthesis of quaternary α-perfluoroalkyl lactams via electrophilic perfluoroalkylation
Efficient protocols enabling the rapid installation of trifluoromethyl, as well as further functionalized fluoroalkyl groups by an electrophilic perfluoroalkylation of lactam-derived ketene silyl amides (KSAs) using hypervalentiodinereagents 1...