Lithium- α-lithioacetate and β-lithiopropionate: useful intermediates in organic synthesis

The reaction of chloroacetic acid and 3-chloropropionic acid with a base (LDA or BunLi, respectively) and then with an excess of lithium and a catalytic amount of 4,4′-di-tert-butylbiphenyl (DTBB, 5%) in the presence of different electrophiles [ButCHO, PhCHO, Et2CO, (CH2)5CO, PhCOMe] in THF at −78°C leads, after hydrolysis with water, to the expected hydroxy acids, which in the second case are directly cyclised under acidic conditions to give the expected γ-lactones.