[nj_bartel]

Yeah, that was the plan.  Completely slipped my mind I'd form another grignard.

[aldoxime_amine]

My 8 steps: ( i am posting because others have also posted theirs..)

1. Do aldol condensation on the aldehyde. (donot dehydrate)
2. haloform reaction, acidify.
3. Protect aldehyde by making the acetal
4. Chlorinate using SOCl2
5. AlCl3 + benzene + compound in 6
6. Wolff kisnher (or Red P +HI; not a nice lab procedure; any alternatives can anyone suggest?)
7. Cleave the acetal and subsequent oxidation simulataneously using hot aqeous acidified KMnO4
8. SOCl2; AlCl3

(My last step is actually 2 steps lol)

Doubtful step: second beacuse aldol product may again form

@azmanam Can you post your scheme?

[azmanam]

2. haloform reaction, acidify.

The product of the aldol add'n is the beta-hydroxy aldehyde.  You'll have to oxidize the alcohol to get the methyl ketone.  But then the methylene protons in the middle are the most acidic.  I'd acetal protect the aldehyde, then oxidize the alcohol, then iodoform.

7. Cleave the acetal and subsequent oxidation simulataneously using hot aqeous acidified KMnO4

I'd also be afraid you'd cleave the benzylic carbon to get benzoic acid and clip that alkyl group right off.

Here's what I did... again, not that it's the best or most efficient (in fact, I think it's rather inefficient).  In looking back through it, the problem step is the 2nd F.C. acylation... I'd be afraid it would cleave the acetal p.g. and kill the regioselectivity of the F.C. acylation. 

[azmanam]

To get around the 2nd F.C. problem, I guess you could not oxizide benzyl alcohol (product of LAH reduction) to benzaldehyde, but instead protect as TBS ether.  Then F.C., deprotect, oxidize to aldehyde, aldol, reduce.

I think a better 2nd generation synthesis, though is a hybrid of mine and aldoxime_amine...  I think tethering one long chain to form the 5-membered ring is probably better than tethering 2 short chains off the benzene ring.

[combatwombat]

Wow, this problem was even tougher than I thought. How's this pathway:

1. Make enolate of acetaldehyde, react with benzaldehyde and NaOH to get the Claisen-Schmidt product

2. Treat with H2, Pd to get rid of C-C double bond

3. Use KMnO4 to turn aldehyde into carboxylic acid

4. SOCl2 to change the OH into a Cl

5. AlCl3 to attach it to the benzene ring

Is this workable? The only sketchy part seems to be making the enolate of acealdehyde - it might react with other acetaldehyde molecules to make unwanted products...

[azmanam]

yeah, that's essentially the 2nd half of the hybrid route.  again, KMnO4 will probably clip off the entire alkyl group.  The crossed aldol will need to be acidic, not basic, to get the elimination product.

You're right that acetaldehyde will probably self-condense if you add base (or acid) to a mixture of benzaldehyde and acetaldehyde.  To overcome that, you change the order of addition.  Add acetaldehyde SLOWLY to a mixture of benzaldehyde and acid.  This will ensure that as soon as the enol forms, it reacts with benzaldehyde - present in MUCH greater excess) and not with itself.  this only works if 1 aldehyde does not have alpha protons  (if it is not enolizable).

[aldoxime_amine]

But the methyl carbinol is oxidized to the ketone in situ. Here is a reference.
http://en.wikipedia.org/wiki/Haloform_reaction

An alternative to the KMnO4 step in my synthesis could be probably Fehlings' solution.

[azmanam]

But the methyl carbinol is oxidized to the ketone in situ

really?  i didn't know that.  thanks for the link

[aldoxime_amine]

Regarding your first synthesis (azmanam) I think the second F.C. is slightly doubtful because of steric hindrance..?

But your second synthesis is very nice. That strange reaction what is it called (the one using tosyl hydrazine)? any links?

[azmanam]

tosyl hydrazine, yes.  very nice, easy, reaction I've done several times on a,b-unsaturated esters.  Generates diazene in situ.  Ene reaction to hydrogenate C=C and liberate N2.

http://en.wikipedia.org/wiki/Diazene
http://www.jce.divched.org/Journal/Issues/1965/May/jceSubscriber/JCE1965p0254.pdf (subscription might be required).

For more fun, (but more dangerous conditions), try this paper.  I've used to to reduce a,b-unsat. ketones in the presence of terminal alkenes no problem.

http://dx.doi.org/10.1021/jo00354a027