Standard Article

Tiffeneau-Demjanov Ring Expansion

(Tiffeneau-Demjanov Rearrangement)

Published Online: 15 SEP 2010

DOI: 10.1002/9780470638859.conrr623

Comprehensive Organic Name Reactions and Reagents

Comprehensive Organic Name Reactions and Reagents

How to Cite

2010. Tiffeneau-Demjanov Ring Expansion. Comprehensive Organic Name Reactions and Reagents. 623:2777–2781.

Publication History

  1. Published Online: 15 SEP 2010

Abstract

It is a multistep extension of the Demjanov rearrangement to elongate the carbonyl compounds by one more carbon atom, by means of conversion of the carbonyl compound into a β-amino alcohol followed by diazotization with nitrous acid. Therefore, this reaction is generally known as the Tieffeneau–Demjanov ring enlargement. The study finds that in most cases, the Tiffeneau–Demjanov reaction is used to expand the ring of cyclic ketones. It has been reported that the stereochemistry of migrating carbon is generally retained after the rearrangement. For cyclic ketones, the yield of rearrangement decreases along with increasing ring size. This rearrangement has also some limitations and is considered very useful for the preparation of cyclic ketones.

Keywords:

  • cyanohydrin;
  • hexahydrofluorenone;
  • steric strain;
  • β-amino alcohols