Based on a Plenary Lecture to the Symposium on the Chemistry of Small Rings (Louvain, Belgium, September 12–15, 1967).
Synthesis of Cyclopropyl Ethers and Cyclopropanols by Carbene Transfer – Acetolysis of Cyclopropyl p-Toluenesulfonates†
Article first published online: 17 DEC 2003
Copyright © 1968 by Verlag Chemie, GmbH, Germany
Angewandte Chemie International Edition in English
Volume 7, Issue 8, pages 588–598, August 1968
How to Cite
Schöllkopf, U. (1968), Synthesis of Cyclopropyl Ethers and Cyclopropanols by Carbene Transfer – Acetolysis of Cyclopropyl p-Toluenesulfonates. Angew. Chem. Int. Ed. Engl., 7: 588–598. doi: 10.1002/anie.196805881
- Issue published online: 17 DEC 2003
- Article first published online: 17 DEC 2003
- Manuscript Received: 8 SEP 1967
- Cyclopropyl p-toluenesulfonates
The reaction of chloromethyl phenyl ether with butyllithium in olefins yields phenoxy-cyclopropanes. 1-Chloro-1-phenoxycyclopropanes can be prepared in a similar manner, though the yields are poor. Alkoxycyclopropanes are formed when dichloromethyl alkyl ethers are treated with methyllithium/lithium iodide in the presence of olefins. Cyclopropanols can be obtained in good yields by reaction of (β-chloroethoxy)cyclopropanes either with butyl- or ethyllithium or with bases. – As was shown by acetolysis experiments with cyclopropyl p-toluenesulfonates having a known steric configuration, the rearrangement of a cyclopropyl derivative into an allyl cation proceeds in accordance with the Woodward-Hoffmann-DePuy rule. The solvolysis of exo-bicyclo[n.1.0]alkyl p-toluene-sulfonates is assumed to proceed via “semi-open” intermediates, which are somewhere between an allyl cation and a cyclopropyl cation.