5- Hexenyl radical methyl substituted

Photoinduced electron transfer promoted cyclization reactions of a-silyl-methyl amines have been described by two groups. The group of Pandey cyclized amines of type 135 obtaining pyrrolidines and piperidines 139 in high yields [148]. The cyclization of the a-silylated amine 140 leads to a 1 1 mixture of the isomers 141 and 142 [149]. The absence of diastereoselectivity in comparison to analogous 3-substituted-5-hexenyl radical carbocyclization stereochemistry [9] supports the notion that a reaction pathway via a free radical is unlikely in this photocyclization. The proposed mechanism involves delocalized a-silylmethyl amine radical cations as reactive intermediates. For stereochemical purposes, Pandey has investigated the cyclization reaction of 143, yielding... 

Cyclization of 5-hexenyl radicals has been compared computationally (BLYP/31-I-G ) with 2-oxo-5-hexenyl radicals." Several methyl-substituted analogs... 

Beckwith ALJ, Easton JC, Lawrence T, Serelis AK (1983) Reactions of methyl-substituted 5-hexenyl and 4-pentenyl radicals. Aust J Chem 36 545-556... 

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