Alcohols: Multi-Step Synthesis - Set #II
Suggest a synthetic scheme for the conversion shown on the left using the starting materials shown below. Work each problem backwards, and draw the structures of the intermediates required for the conversion, and the reaction conditions necessary for each step.Click the mouse on the buttons to view the synthetic logic for each step, the structures of the intermediates and the solution to the problem;
click here to view the potential starting materials.
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Working backwards, this molecule is a primary alkyl chloride. We can make those by reaction of the corresponding alcohol with thionyl chloride in pyridine. For a starting material, we need a mono-substituted benzene which can be converted to benzyl alcohol. All three of the potential starting materials could be used
Working backwards, this molecule is a primary alkyl chloride. We can make those by reaction of the corresponding alcohol with thionyl chloride in pyridine, as shown above. For a starting material, we need a mono-substituted benzene which can be converted to benzyl alcohol. All three of the potential starting materials could be used; suggest a synthesis utilizing bromobenzene.
Bromobenzene is first converted to a Grignard reagent by reaction with Mg/ether, and then is converted to the alcohol by reaction with formaldehyde. In a second step,benzyl alcohol is reacted with thionyl chloride to give the final product. The intermediate alcohol could also be prepared by reduction of benzaldehyde, or by oxidation of toluene to the carboxylic acid, followed by reduction using LiAlH4.