Intramolecular Reaction of a Phenonium Ion. Novel Lactonization of 4-Aryl-5-tosyloxypentanoates and 4-Aryl-5-tosyloxyhexanoates Concomitant with a Phenyl …
The novel lactonizations of methyl 4-aryl-5-tosyloxypentanoate 1 and 4-aryl-5- tosyloxyhexanoate 3 concomitant with a phenyl rearrangement are reported. The lactonizations were promoted by silica gel or heating in various solvents. By examining the effects of substituents of the aromatic ring on the reactivity, it was found that the reaction proceeded via a phenonium ion. This finding was supported by the stereochemical results ...