Regioselective directed lithiation of N-Boc 3-hydroxypyrrolidine. Synthesis of 2-substituted 4-hydroxypyrrolidines
Abstract
N-Boc 3-hydroxypyrrolidine 1 undergoes directed C-lithiation at C5 and not, as previously reported, at C2; the resulting dilithiated intermediate 6 has been trapped by a range of electrophiles to give 2-substituted 4-hydroxypyrrolidines 7.