[blondie915]

Show the reagents for the transformation below (see image). It must be done in only five steps.

My thoughts: What I did was add hexavalent Cr to oxidize the alcohol, which turned it into a secondary ketone, to that I added a grignard (phenyl-magnesium-bromide), which gave me 2-phenyl-2-butanol (I know that probably isn't that IUPAC name). I am stuck when I get to this point because I know that I cannot oxidize a tertiary alcohol, which I have created. If someone could point me in the right direction, I would really appreciate it. Thank you!

[spirochete]

Think about the last step of the synthesis. How could you do it in one step? A grignard reagent like you said is reasonable, but it will be with a different reactant. Then think about what steps you need to get to that final step. It involves some combo of oxidation/reduction/elimination.

[OCSaviour]

Step 1: Create alkene from the butan-2-ol
Step 2: Convert the alkene into a diol.
Step 3: Convert the alkene into a diketo.
Step 4: Make the diketo react with two moles of PhMgBr
Step 5: convert the OMgBr groups into OH.