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Cyclopropanes from Unsaturated Compounds, Methylene Iodide, and Zinc-Copper Couple

  1. Howard E. Simmons1,
  2. Theodore L. Cairns1,
  3. Susan A. Vladuchick1,
  4. Connie M. Hoiness2

Published Online: 15 MAR 2011

DOI: 10.1002/0471264180.or020.01

Organic Reactions

Organic Reactions

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.

Author Information

  1. 1

    Central Research Department E. I. du Pont de Nemours and Co., Inc.,, Wilmington, Delaware

  2. 2

    ICI America, Inc.,, Wilmington, Delaware

Publication History

  1. Published Online: 15 MAR 2011

Chemistry Terms

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Abstract

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.

Keywords:

  • cyclopropanes;
  • methylene iodide;
  • zinc-copper couple;
  • alkenes;
  • zinc reagent;
  • hydroxyalkenes;
  • allenes;
  • angular methylation;
  • experimental conditions