Organolithium addition to carbonyls

5 real reactions from the literature, on carboxylic acids, carboxylates, α,β-unsaturated esters and six-membered cyclic ketones. Each scheme shows starting materials, conditions and products, with the yield and reference where the source reports them.

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1. Organolithium addition: (+)-2-methylpentanoic acid (a carboxylic acid) with 1) 2 equiv EtLi, Et2O; 2) NH4Cl / H2O gives (4S)-4-methylheptan-3-one (the dialkyl ketone).

   Organolithium additionChem. Commun. 2002, 1680

2. Organolithium addition: cyclohexanecarboxylate and lithium ion with Li; 1) CH3Li, ether; 2) aq. HCl gives cyclohexyl methyl ketone.

   Organolithium additionOrg. Synth. Coll. Vol. 5, p. 775

3. Organolithium addition: a carboxylic acid with 1) 2 equiv PhLi, Et2O; 2) NH4Cl / H2O gives the aryl ketone.

   Organolithium additionJ. Am. Chem. Soc. 1987, 109, 5285

4. Organolithium addition: ethyl methacrylate (an α,β-unsaturated ester) with 1) 2.2 equiv MeLi, Et2O; 2) NH4Cl / H2O gives 2,3-dimethyl-3-buten-2-ol (the allylic alcohol).

   Organolithium additionAngew. Chem. Int. Ed. 2009, 48, 3648

5. Organolithium addition: cyclohexanone (a six-membered cyclic ketone) and an organolithium with 1); 2) H+ workup gives 1-[methoxy(trimethylsilyl)methyl]cyclohexan-1-ol (the tertiary alcohol).

   Organolithium additionRealOChem worksheet