On Rhodium's page there is around a procedure from Osmium 1] how to convert isosafrol to its methylketone. Here are two results for anethole and asarone using Osmiums approach (slightly modified) hoping to increase the intellectual honey of the hive bees.
The procedure is a two step reaction, first preparing the epoxide, which is then re-arranged to the ketone via a Lewis acid in EtOAc.
Step 1: Epoxide 10ml of the propenylbenzene (anethole/asarone) are added to 150ml of a 1:1 mix of MeOH and MeCN. 1.1 mol (based on the olefin of course) 30% H2O2 saturated with Na2CO3 is added at room temp over 20 minutes under stirring. After addition is completed, the mix is stirred at rt for 24hours 2]. The MeOH/MeCN solvent is removed by vac dest (approx 100Torr) using a waterbath with 40-45DegC 3]. The remaining residue is taken up with ether, washed with water and dried with MgSO4. Evap of the ether (waterbath with 40-45DegC) gave a clear light yellow oil. (for anethole and asarone).
Step 2: Rearrangement The oil is added to 150ml EtOAc and 1.9g LiBr is added. The Ethylacetate is refluxed for 24hours 4]. Then the EtOAc is washed with water, dried with MgSO4 and evaporated.
Anethole: a slighly red viscous oil remained. Bisulfit test positive, so all of the residue is treated with a concentrated bisulfite solution, the whole stuff gave a heavy cristall mass 5], which was vac filtered washed with cold water, EtOH and dried. Yield about 80% bisulfite compound.
Asarone: a deeper brown oil remained. Bisulfite test negative! The residue was therefore vacuum destilled and at 160-165DegC under 6Torr 4-5ml of a green viscous oil destilled over. In the flask a deep red oil remained. The green destillate did give a negative bisulfite test as well (green color disappeared!). The green oil can be washed away from the glasware with hot water.
Big question: what have happened here? 1]
http://rhodium.lycaeum.org/chemistry/safrolepoxide.html
2] After an hours or so, the yellow color of the asarone has disappeared. Solvent mix is water clear at this time.
3] The mix of MeOH and MeCN is recovered and can be re-used next time. This is an advantage with respect to Osmiums procedure.
4] The use of MeCN instead of EtOAc as mentoined in an US patent gave only 50% yield in case of the anethole.
5] Use a bottle with a wide stopper, otherwise you can't remove the compound!
Carpe Diem