Pyrrolidine ring construction synthesis

The combination of the characteristics of the fullerene skeleton with the fused pyrrolidine ring is of great importance for the construction and synthesis of materials with novel properties. The most attractive feature of fulleropyrrolidines is... 

Intramolecular displacement of benzylic chlorides by nitrile anions was previously demonstrated as an efficient method making substituted pyrrolidines " however, the question of enanti-oselectivity was not addressed. Recent works on the synthesis of substituted cyclopentane showed that intramolecular enolate displacement of benzylic phosphate proceeded in clean inversion. Thus, it was envisioned that an appropriately substituted cyano phosphonate could be used to construct the pyrrolidine ring (Scheme 5.23). This intermediate could potentially be produced by the addition of a fert-butylamine to acrylonitrile. The desired amine could be produced via reaction... 

Lepadiformine is a not-too-complicated tricyclic alkaloid, which finds some attention in the synthetic community [31], The first synthesis hy Funk [32] constructs the rings sequentially (Scheme 11.24). The functionality initially needed to facilitate the Diels-Alder addition has been cleverly used to build the pyrrolidine ring. 

Chiou et (d. [81] investigated the hydroformylation-acetalization in the framework of the synthesis of pyrrolidinoindolines and tetrahydrofuranoin-dolines (Scheme 5.89). The hydroformylation occurred in the a-position of the aryl ring. Double cyclization constructed the fused pyrrolidine ring in a stereoselective maimer. Based on this protocol, a variety of pharmacologically important alkaloids were synthesized. By application of the corresponding allyl alcohol as starting material, the THF-based physovenine was prepared. 

Finally in 2005, Hutt and Mander reported their strategy for the synthesis of nominine (Scheme 1.3) [29], The approach relies upon construction of the steroidal ABC carbocyclic ring structure followed by stepwise preparation of the fused aza-ring system. In the key sequence of the synthetic study, enone 50 was oxidized to dienone 51 with DDQ followed by Lewis acid-catalyzed intramolecular conjugate addition of the methylcarbamate to the newly formed dienone to deliver pyrrolidine 52. 

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