Synthesis of Different types of Heterocycles are used by Claisen rearrangement reaction

Abstract

The Claisen rearrangement is a powerful tool for carbon-carbon bond-forming reaction which was discovered by Rainer Ludwig Claisen. The discovery of the Claisen rearrangement nearly a century ago accessible a potentially useful synthetic tool to the organic chemist. Utility of this rearrangement over the decades has been realized and the reaction has drawn the consideration of numerous research groups, which has been showed in the number of publication on the topic published in the literature. The Claisen rearrangement continues to be the focus of considerable synthetic chemistry research effort. A number of examples showing the use of the Claisen rearrangement in the preparation of a widespread of synthetically interesting building blocks and natural or biologically active compounds are reflected.  The [3,3] sigmatropic rearrangement of allyl vinyl ethers, which permits the preparation of γ,δ-unsaturated carbonyl compounds, is worthy of study due to its special synthetic relevance as well as the large number of theoretical studies generated. The definition for claisen rearrangement can be described as “the thermal isomerization of an allyl vinyl ether or of its nitrogen or sulfur containing analogue derivatives to afford a bi-functionalized molecule.

Keywords: Claisen rearrangement, E)-ethyl 3-(allyloxy)but-2-enoate, NH₄Cl, Baylis–Hillman reaction, catalysts, diazabicyclo-(2,2,2)-octane (DABCO), allyl vinyl ethers, quinuclidine