Ethers, allyl vinyl discovery

Since its discovery in 1912, the Claisen rearrangement of allyl vinyl ethers (1 - 2 equation 1) has become one of the most powerful tools for stereoselective carbon-carbon bond formation. Much of its current popularity is due to the subsequent development of a series of new variants of this 3,3-sigma-tropic rearrangement. In 1940, Carroll reported the base-catalyzed rearrangement of -keto esters and allylic alcohols to alkenic ketones (3 4 5 equation 2). Twenty years later. Saucy and Marbet dem-... 

Since its discovery in 1912 [1], the Claisen rearrangement, namely thermal [3,3]-sigmatropic rearrangement of an allyl vinyl ether, has received great attention as one of the most powerful methods for stereoselective carbon-carbon bond formation. Metal catalysis has been introduced to significantly accelerate the Claisen rearrangement even at room temperature. A hterature survey on metal catalysis of Claisen rearrangements is available in excellent reviews by Lutz, Overman, Frauenrath and Hiersemann [2]. 

Since its discovery in 1912, the Claisen rearrangement [2] of aryl or allyl vinyl ethers became of increasing importance and various versions of this [3,3] sigmatropic rearrangement appeared in the second part of 20th century (Scheme 6.1). 

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