One Equivalent of Ethanethiol Reacts with a Naphthalene-1,4-Dione Derivative to Yield

Essay

One equivalent of ethanethiol reacts with a naphthalene-1,4-dione derivative to yield primarily A or B, but not both.
​a. Show a reaction mechanism for the formation of the favored product, and state in 10 words or less why your choice is favored over the other.
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b. The actual observed product of this reaction is different than either A or B. The observed product shows no C=O stretch in IR. Show this product below, and in 10 words or less, state why this actual product forms.