[nexisrocks]

I am attempting to find a mechanism for this product:



Any organic compound containing up to 7 carbon atoms may be incorporated into the product and any other reagent may be used.

I thought about starting from 1,3-heptadiene, brominating and using organopalladium chemistry to form 2-methyl-1-cyclohexene.  However, wouldn't the bromination add a bromine to both double bonds?

Then I thought about starting with 2-methyl-1-cyclohexene itself.  However, I'm unsure how to add the hexene group onto the ring.  I thought about doing an organopalladium reaction, however this would first require a bromination of the ring, which would destroy the double bond.  Thus, it doesn't work.

I'm really not sure how to do this.

Can anyone help?

[movies]

Can you not start from the brominated compound?  It still only has 7 carbons.

If I really wanted to make this compound with a Pd coupling reaction, I would start with 2-methylcyclohexanone and convert it to the enol triflate (LDA; PhNTf₂), which can then be used like a vinyl bromide.

I'll leave the other coupling partner up to you, but I would recommend a Stille reaction because the tin reagent you need would be very easy to make....

[Fry]

Diels alder of 1,3-pentadiene with acrolein, hydrogenation to remove the double bond, alpha bromination then base to give correct unsaturation, and then a wittig to give the chain alkene?

Intramolecular aldol condensation with 1,7-diketoheptane, allylic bromination + grignard + MeI to introduce the methyl group and then a wittig reaction for the side chain?