You can oxidize the cinnamyl alcohol to cinnamaldehyde and reduce its tosylhydrazone with NaBH4 to allylbenzene: https://www.thevespiary.org/rhodium/Rhodium/chemistry/cinnamaldehyde.html (https://www.thevespiary.org/rhodium/Rhodium/chemistry/cinnamaldehyde.html)
You cannot halogenate cinnamyl alcohol with any HX acid without touching the double bond.
Rhodium... thanks for the info on going to the allylbenzene from the OH and the many other references and comments you've been providing, they are most helpful in teach me good chemistry.
Kinetic thanks for the info as I see it I have a good way to go to the CH3 and also to a CX from the OH. As I 've bee looking at the dialkylamino -chloro addition to the non conjugated cinnamyl chloride https://www.thevespiary.org/rhodium/Rhodium/pdf/archive/vinylic.aminochlorination.pdf (https://www.thevespiary.org/rhodium/Rhodium/pdf/archive/vinylic.aminochlorination.pdf)
, for which I feel the chlorine can be removed with hydrogenation and end up with desired product ,except a dimethylamine as oppose to a methylamine on the C2.
Saludos, from Latin America....java