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Reduction and Related Reactions of α,β-Unsaturated Carbonyl Compounds with Metals in Liquid Ammonia

  1. Drury Caine

Published Online: 15 MAR 2011

DOI: 10.1002/0471264180.or023.01

Organic Reactions

Organic Reactions

How to Cite

Caine, D. 2011. Reduction and Related Reactions of α,β-Unsaturated Carbonyl Compounds with Metals in Liquid Ammonia. Organic Reactions. 23:1:1–258.

Author Information

  1. Georgia Institute of Technology, Atlanta, Georgia

Publication History

  1. Published Online: 15 MAR 2011

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Abstract

This chapter is concerned with the reduction and related reactions of alpha,beta-unsaturated ketones by alkali and alkaline earth metals in liquid ammonia. Upon treatment with a metal in liquid ammonia (usually containing an ether co-solvent) a simple alpha, beta-unsaturated ketone is converted into the metal enolate corresponding to the saturated ketone. Research during the first half of the 20th Century revealed that a variety of organic compounds undergo reduction with metals in liquid ammonia but preparative metal-ammonia reductions of alpha,beta-unsaturated carbonyl compounds were apparently not described until 1951. In addition to affording a remarkable degree of stereoselectivity, many metal-ammonia reductions of unsaturated carbonyl systems can be preformed in a variety of functional and protective groupings and the reaction is generally free of the rearrangements sometimes observed when chemical reduction methods are used. The unique features of metal-ammonia reductions and related reaction have led to their wide application in total synthesis and transformations.

Keywords:

  • reduction;
  • alpha,beta-unsaturated carbonyl compounds;
  • metals;
  • liquid ammonia;
  • dimerization;
  • streochemistry;
  • metal enolates;
  • lithium enolates;
  • experimental procedures