[bc_juno]

Hey all,

I have to figure out how to synthesize 2,3,4,-trimethylpentan-3-ol from ethanol using addition, substitution, and elimination using the least number of steps. I need to find the related equations...I am new to organic chem, your help would be much appreciated!!! thanks in advance

[english]

Well, there are several ways to synthesize things like this (almost endless possibilities).

What's the simplest carbon skeleton you can start with?  Acetylene?

[bc_juno]

It has to be synthesized with Ethanol as the only source of carbon and I have to use Addition, Elimination, and substitution. Also, C-C bonds can only be made using Grignard reagents.

[shelanachium]

One possibility:

CH3CH2OH ----> CH3CO2H (oxidation)

CH3CO2H + CH3CH2OH ---> CH3COOCH2CH3 + H2O (esterification)

Then reaction of 2 moles of isopropyl Grignard reagent with the ester - a standard method of making a teriary alcohol.

CH3COOCH2CH3 + 2 (CH3)2CHMgBr ---> (CH3)2CH-C(OH)CH3-CH(CH3)2 + MgBr2 etc.

                                                        2,3,4 trimethylpentan-3-ol

But no elimination step!

[Ak]

I was told that this could be made from pentan-3-ol, so this may sound stupid to you pros...but how do you synthezise pentan-3-ol from ethanol? Thanks in advance

[sjb]

Well, consider what shelanachium has posted, look at the differences in the carbon chains, and see how they're put together.

Perhaps.

[nox]

I apologize for reviving a dead topic, but I stumbled across this question the other day while being bored and it intrigued me

The original question can be found at http://www.utm.utoronto.ca/~w3chm140/examquestions07-08.pdf it is question #8

I think the hardest part here is that the ONLY source of carbon is from ethanol, and no matter how hard I try I just can*not* create the branching required in the product, and this is very frustrating (and quite embarassing since I've already done org 2 + 3 ) The question essentially boils down to this:

I mean I did manage to come up with creating an isopropanol unit from ethanol but it's too long and too extreme and overall yield would likely be crap:
EtOH + SOCl2 + pyridine + heat ---> ethylene + ozone ---> formaldehyde x 2 + NaBH4 ----> MeOH x2 + SOCl2 ---> methyl chloride + Mg ---> MeMgCl + acetaldehyde (from EtOH oxidation with PCC) ---> isopropanol

[azmanam]

ethylene + ozone ---> formaldehyde x 2

That's good.  I like that.

You can use that synthesis of isopropanol and shelanachium's suggestion on making a tertiary alcohol to make the molecule you've drawn.