i'm curious to the possibility of synthesizing safrole from 1,3-benzodioxole and allyl bromide using the zinc method: Post 408642 (https://www.thevespiary.org/talk/index.php?topic=12131.msg40864200#msg40864200)
(Kinetic: "Zinc promoted Friedel-Crafts acylation", Novel Discourse).
I knows alkylations can me done this way but I am unsure whether the double bond on the allyl bromide would in some way hinder the reaction.
Thanks.
First, you will not get only the isomer you desire, because AFAIK, the allyl chloride or bromide will also alkylate ortho to the methylenedioxy structure.
Second, using normal friedel-crafts methods will generate HBr acid, which will tend to add across the allyl double bond, and possible cause multiple alkylations and polymerization. There are ways around this:
Post 468541 (missing)
(ning: "high-yielding OTC allylation of aromatics, anyone?", Chemistry Discourse) scrubs up HX with supported K2CO3
Post 515205 (https://www.thevespiary.org/talk/index.php?topic=12245.msg51520500#msg51520500)
(psyloxy: "TsOH - best Friedel-Crafts catalyst ever ?!", Novel Discourse) uses tosic acid to catalyze the magical alkylation
anyhow, it's not so easy as it seems.