PROCESS FOR THE DIASTEREOSELECTIVE PREPARATION OF PIPERIDINES FUNCTIONALIZED IN POSITIONS 2 AND 4 FOR USE AS SYNTHESIS INTERMEDIATES

摘要

The invention concerns a method for preparing, with diastereoselective induction, a piperidine monosubstituted in position 4 and functionalised in position 2, comprising steps which consist in: (i) reacting the corresponding N-protected piperidine, monosubstituted in position 4 and non-functionalised in position 2, with a strong base so as to form the negatively charged corresponding carbanion in position 2; then (ii) reacting said carbanion with an electrophilic reagent, with a volume less than 80 ANGSTROM 3 or more than 100 ANGSTROM 3.