Pyrrolinone-pyrrolidines

The action of phosphorus halides on pyrrolinones and related compounds offers an alternative route to chloropyrroles. Yields of around 60% of 2,5-dichloropyrroles were obtained in this way from N-substituted succinimides (82ZC126). Vilsmeier reaction of N-alkylsuccinimidals formed chlorinated pyrrole aldehydes in modest yields (90CJC791), and there are other examples [66YZ158 81H(15)547]. A useful synthesis of chloropyrrole-2-carboxylates employed the action of phosphorus pentachloride on pyrrolidin-2-one-5-carboxylates (40) (87CB45) (Scheme 15), and in a Pummerer-type reaction pyrrol-3-yl sulfoxides were transformed by thionyl chloride into chloropyrroles. Yields were increased to >80% by the use of oxalyl chloride (88JOC2634) (Scheme 15). 

Treatment of the quaternary ammonium salt PhC=CCH2NMe2CH2COPh Br" with sodium hydroxide gives, inter alia, the betaine (98). Controlled-potential electrolysis of 7-nitro-ketones on a mercury cathode yields 1-pyrroline 1-oxides, pyrrolines, or pyrrolidines, according to conditions thus the oxide (99) is obtained from the compound 02NCMe2CHPhCH2C0Ph. The pyrrolinone (101) results from autoxidation of the furan derivative (100). Irradiation of the amide (102) leads to the pyrrolidinone (103) by an unprecedented [1,6] shift of hydrogen. " ... 

Asymmetric synthesis of pyrrolidines and pyrrolinones. This chiral -hydroxy-amine (1) reacts with a y-keto acid in refluxing toluene to form a chiral bicyclic lactam 2 in 75-98% yield. Treatment of 2 with excess alane, generated from AlCly and LiAlH4,... 

Use of the retro-Diels—Alder reaction in the synthesis of chiral pyrrolidine and pyrrolinone products has been described by several groups. The... 

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