The β-cleavage reaction in ethers

✍ Scribed by Steven L. Bernasek; R. Graham Cooks

• Book ID: 102557513
• Publisher: John Wiley and Sons
• Year: 1970
• Tongue: English
• Weight: 179 KB
• Volume: 3
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210030115

✦ Synopsis

p-Cleavage in n-butyl ethyl ether occurs neither by simple bond fission with oxiranium ion formation nor by a mechanism analogous to the y-cleavage reaction in carbonyl compounds, but instead it involves skeletal rearrangement within the butyl chain.

KRAFT and Spiteller's study of the y-cleavage reaction in carbonyl compounds and their derivatives1 prompts inquiry into the mechanism of the P-cleavage reaction in ethers. This reaction is of some importance in n-butyl and n-pentyl but not in higher ethers and the sharply increased abundance of the product ion at low electron energies suggests that a rearrangement is involved.2 n-Butyl ethyl ether (I) shows a @-cleavage product ion (m/e 73, [C,H,O]+) of * The spectrum we obtained was essentially identical with that given in ref. 3. t The uncertainty in this figure is due to the low relative abundance of the molecular ion and the occurrence of a low activation energy [M -H.]+ process.

* This result also rules out any contribution by C-0 cleavage with charge retention by the alkoxyl group.