Cyclopropanes from Unsaturated Compounds, Methylene Iodide, and Zinc-Copper Couple
Published Online: 15 MAR 2011
Copyright © 2004 by Organic Reactions, Inc. Published by John Wiley & Sons, Inc.
How to Cite
Simmons, H. E., Cairns, T. L., Vladuchick, S. A. and Hoiness, C. M. 2011. Cyclopropanes from Unsaturated Compounds, Methylene Iodide, and Zinc-Copper Couple. Organic Reactions. 20:1:1–131.
- Published Online: 15 MAR 2011
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The reaction of the organozinc reagent prepared from methylene iodide and zinc-copper couple with substituted unsaturated compounds has proved to be a versatile and convenient method for the synthesis of cyclopropanes. The synthesis is stereospecific with regard to the stereochemistry of the unsaturated compound and is usually free from serious side reactions; it can be carried out under mild conditions in diethyl and affords cyclopropanes often in good yields. This method can be easily adapted to large-scale preparations. Two useful variations of the cyclopropanation reaction have appeared which involve the same or a similar organozinc intermediate: (1) diazomethane reacts with iodide in ether to form a reagent which converts unsaturated compounds to cyclopropanes; (2) methlyene iodide and diethyl zinc react in ether in the presence of unsaturated compounds to cyclopropanes. Processes are known in which a divalent carbon fragment adds to carbon-carbon double bonds either as a free carbene or as an organometallic complex.
- methylene iodide;
- zinc-copper couple;
- zinc reagent;
- angular methylation;
- experimental conditions