[english]

I mean your product.  For example the reaction go half,  there are 50% mole of the ester left and  50% mole of the ketone product formed,  what will happen when you add MeMgCl into the mixture? I wish my language can be stronger.

How about this way:

http://img485.imageshack.us/my.php?image=lipsyn1edit2le3.jpg

I think there might be problem with adding acid at certain points

Can you add that image directly on here?  That image upload is difficult to see; resolution is low.

[english]

• Use MeOH/MeO^- for first step instead of NaOH.  This ensures no competition with hydrolysis.
• Need HCl for addition at a-carbon in 1st step (add after reaction with NaOH)
....the a-carbon of your beta keto ester is sufficiently acidic to undergo further additions.  HCl ensures that it stays protonated.  An equivalent amount of HCl is required.

There might be more things to correct...but that's what I see as of now.

[Sam (NG)]

• Use MeOH for first step instead of NaOH.  This ensures no competition with hydrolysis.
• Need HCl for addition at a-carbon in 4th step (add after reaction with NaOH)

There might be more things to correct...but that's what I see as of now.

This will deprotect the end with the acetal on. Also, when you add the diol to protect the aldehyde, what's to stop the ketone getting protected as well?

[edit]  After the fourth step, the enolate anion for the base catalysed aldol should look like this:

[english]

Meant to say that you need HCl in step one, added after NaOH.  I edited my comment in previous post.

[refid]

Meant to say that you need HCl in step one, added after NaOH.  I edited my comment in previous post.

I see what you mean, forgot that the deprotonation of that a-hydrogen is the driving force of ester condensation.

Question:
Would I be able to do a grignard, without doing the hydrolysis step (acid work up ) & directly oxidize the MgCl complex off?



since the Acid work up of the grignard step will prematurely disrupt the AcO- protecting my alcohols

[english]

Grignard reagents are very reactive, and quite difficult to stop at the ketone stage.  There's better ways to get your ketone.