Intramolecular Reaction of a Phenonium Ion. Novel Lactonization of 4-Aryl-5-tosyloxypentanoates and 4-Aryl-5-tosyloxyhexanoates Concomitant with a Phenyl Rearrangement<sup>1</sup>
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 for the lactonization of opticalactive 1. Silica gel-promoted lactonization of 1 gave only gamma-lactone 2, whereas that of 3 afforded gamma-lactone 4 and delta-lactone 5. These lactonizations proved to be kineticallycontrolled. On the other
The reaction of methyl (E)-4,5-epoxypent-2-enoate with arylcopper: the unique role of boron trifluoride in determining regioselectivity
作者:Shinji Nagumo、Shigeyuki Irie、Hiroyuki Akita
DOI:10.1039/c39950002001
日期:——
Excess BF3 causes regioselectivity reversion in the reaction of methyl 4,5-epoxypent-2-enoate 1 with Ph2CuLi; this is rationalised by a two step conversion via methyl 4-bromo-5-hydroxypent-2-enoate 5.