The base-promoted rearrangement of an a-haloketone to a carboxylic acid, known as the Favorskii rearrangement, is illustrated by the conversion of 2-chlorocyclohexanone to cyclopentanecarboxylic acid. Jo Han Sow La NaOH, THF O Nat H3O+ OH NaOH, THF The mechanism involves the following 5 steps: -ō cyclopropanone intermediate 1. Abstraction of a proton to form enolate anion 1; 2. Formation of a cyclopropanone intermediate 2 with expulsion of chloride ion; 3. Addition of hydroxide ion to form tetrahedral intermediate 3; 4. Collapse of the tetrahedral intermediate and breakage of the three-membered ring to form carbanion intermediate 4; 5. Proton transfer to form the rearranged carboxylic acid. For the following reaction, draw the reaction out on paper, and then draw the structure of cyclopropanone intermediate 2 in the window. 1. NaOH, THF 2. H3O* OH
The base-promoted rearrangement of an a-haloketone to a
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