Alcohols: Multi-Step Synthesis - Set #I
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 the mouse on the molecule to reset this frame.
Working backwards, this molecule is an aldehyde and the oxygen is attached adjacent to the carbon in the side-chain which would form the most stable carbocation (anti-Markovnikov regiochemistry). We can make simple aldehydes like this by oxidation of the corresponding anti-Markovnikov alcohol. The alcohol could be formed by hydration of the starting alkene.
Working backwards, this molecule is an aldehyde and the oxygen is attached adjacent to the carbon in the side-chain which would form the most stable carbocation (anti-Markovnikov regiochemistry). We can make simple aldehydes like this by oxidation of the corresponding anti-Markovnikov alcohol using PCC in CH2Cl2. Noting that the alcohol has anti-Markovnikov regiochemistry, suggest a synthesis of the alcohol from the starting alkene.
Styrene (ethenylbenzene) undergoes hydroboration/oxidation to yield the anti-Markovnikov alcohol (the OH group is bonded adjacent to the carbon which would form the most stable carbocation) to give 2-phenylethanol. Simple oxidation using PCC in CH2Cl2 gives the aldehyde.