Answer:
Here's what I get
Step-by-step explanation:
1. Synthesis
(a) Preparation of Grignard reagent
React allyl bromide with magnesium in dry ether.
(b) Grignard reaction
Add allylmagnesium bromide to methyl phenyl ketone. Convert the alkoxide to the alcohol by treatment with aqueous ammonium chloride.
(c) 1,2-Dihydroxylation
React the alkene with tert-butyl peroxide and a catalytic amount of hydrogen peroxide. Decompose the osmate ester with aqueous sodium hydroxide.
2. Mechanism
Here are my proposed steps for the mechanisms.
(a) The 65 % Product
(i) Protonation of the secondary alcohol
(ii) Loss of the protonated OH group to form a secondary carbocation
(iii) Alkyl migration/ring expansion to form a more stable tertiary carbocation
(iv) Deprotonation to form the ketone
(b) The 25 % product
(a) Protonation of the tertiary alcohol
(ii) Loss of the protonated OH group to form a tertiary carbocation
(iii) Hydride shift to form a protonated carbonyl group
(iv) Deprotonation to form the ketone
(c) The 10 % product
(i) Electrophilic aromatic attack by the cation formed in step (b)(ii) to form a cyclopropane intermediate.
(ii) Cleavage of a cyclopropane bond to regenerate the aromatic ring and form a protonated carbonyl group
(iii) Deprotonation to form an aldehyde.