[orgodude9]

I've done all the other questions on this assignment, by looking at the textbook and reasoning it out.

These last two problems have been difficult and I can't think of how to start going about solving them.

Could someone help out? Even if its just offering a starting point and a general gist of where to go.

Thanks so much.



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[phth]

First one is mCPBA and base.  Second synth is Mg RMgBr.  2) benzoyl chloride 3) not really needed because MgClBr will precipitate.  What reactions do you have to choose from?  My guess would be 1)PhCOOH+SOCl2 2)RBr+Mg 3) combine

[quantumnumber]

I'd say what disjigaboo stated.
Maybe the second exercise could be:

1) RBr+Mg RMgBr (formation of Grignard agent)
2)RMgBr + PhCHO (adition of -R to PhCHO)
3) H⁺/H₂O + (Oxidation)

Anyway I think the easiest route is disjigaboo one

[rwiew]

The problem with your ideas for the second reaction is that the ketone will very likely get attacked by the Grignard (i.e. overaddition) to give a tertiary alcohol. I suggest using a Weinreb's amide (http://en.wikipedia.org/wiki/Weinreb_ketone_synthesis if unfamiliar), so (1) will be generation of the Grignard (Mg) or an organolithium (tBuLi), (2) use that on the Weinreb's amide resulting from benzoyl chloride + N-methyl-N-methoxyamine at low T (-78 to 0, as appropriate) (3) acid quench at low T.

[orgopete]

I suggest looking up the Bayer-Villiger reaction. Which group has a greater migratory aptitude, t-butyl or methyl?

I also agree that an acid chloride will react twice with a Grignard. I'd consider reacting a nitrile with a Grignard as an alternate, among many possibilities.

[zsinger]

Definitely want to use Weinrebs IMO.
           -Zack

[spirochete]

Surprised nobody has suggested an Iodoform reaction for the first one. Iodine plus base gives a carboxylate, the conversion of a carboxylate to ester can be done easily in principle by Fischer Esterification. Not sure if the second step would work easily in practice with all that steric hindrance on the ketone but it looks nice on paper.

[Babcock_Hall]

Orgodude,

If you mentally separated the ketone product in between the aromatic ring and the carbonyl carbon, can you think of two reactants that would produce this compound?

[zsinger]

Spiro,
I think haloform would suffer in yields greatly.
       -Zack

[orgopete]

Spiro,
I think haloform would suffer in yields greatly.
       -Zack

I doubt it, but even so, at least it gives the right intermediate. I haven't seen anyone else suggest a successful route. It is also what I was thinking, but not telling directly.

[Babcock_Hall]

I don't believe that the OP showed us his attempts at these two questions.  I am OK with giving hints under those circumstances, which is what I tried to do.