Natural Science Forum / Chemistry / Organic Synthesis / October 2003

CO2 + R-Li -->R-COO(-) Li(+) (fast)
R-COO(-) Li(+) + R-Li --> R2-C-(0(-))2 2Li(+) (slow)
R2-C-(0(-)) 2Li(+) + proton donor --> R2C=O
R2C=O + R-Li --> R3C-OH

What you get depends on reaction conditions including solvent
polarity, temperature, and the steric bulk of R.  Note that many
organolithiums are rather slow to hydrolyze at low temps.

RLi reacts with carboxylic acids Li-salts. The reaction can be stopped
on the stage of the ketone (I remember seing prep for aryl methyl
ketones starting from ArCO2H and MeLi), but the ketone can react
further, of course.

If you carboxylate RLi with CO2, the reaction of the formed lithium
salts of carboxylic acids with excess of RLi will be much slower than
the CO2 addition. So if you want to make the acid, keep the CO2
concentration high and the emperature low(i.e. pour your RLi onto  dry
ice).

Grignard reagents are pretty lazy towards RCO2MgX, so you would have
probably less complications. But I did encounter this problem once
with Grignards also: A reaction of PhMgCl in THF with
benzophenone-3-carboxylic acid (to prepare tritylalcohol-3-carboxylic
acid for solid-phase linker synthesis) has to be done between -40C and
-30C, or the excess of PheMgCl would react with the carboxyl also.

Hi,
I agree with Al and Muhammar. Alkyllithiums are very reactive so, if u
want to
end with a carboxylic acid u'll have to put the organometallic reagent
into solid CO2 (evap. temp. it's about -78 degree C) then adding water
or a mineral acid.
At higher temps. u can obtain a tertiary alcohol but, as Al said, it
depends on alkyl
moiety volume (see steric hindrance and remember about Burgi-Dunitz
trajectory
in a nucleophilic addition at carbonyl group).
Regards,
Narcis

All metals dissolve in gas.  I don't know if this
analogical or homological..   Zr reacts with
electrolyte and hydronium ion to form hydrogen.

Pellet sized zirconium is used for something of
which I am not aware of.

Three mile island evolved 2 gallons of Xenon.

Maybe there is some phatasmagorical
green chemistry fallout of some gallon measure.

Dr. Doug Gillman
Axon instruments, Inc., postal affiliate
Teapot Dome Energy Infrastructure, TI.Realty
TI Texas Instruments, Doug's Home Hearth TVM
Federal AA Hi-Fix Fixtrues, Inc.
Synchrotron Lithography Div
PO Box 16237
Elmwood Place, OH 45216-0237

Dream on nacelles' wind, Caught in tepid Tome, an urge,
  Gin in from the cold.