Remarkable switch of regioselectivity in epoxide ring opening of 3-benzyl-7-oxa-3-azabicyclo[4.1.0]heptane with amines: practical synthesis of trans-4-amino-3-hydroxypiperidines and trans-3-amino-4-hydroxypiperidines

A simple and highly C3 selective ring-opening method for 3,4-epoxypiperidines has been developed. We also describe a practical improvement of the C4 selective ring-opening method using the same N-alkyl substituted 3,4-epoxypiperidines. This method provides access to pharmaceutically relevant trans-3-amino-4-hydroxypiperidines and trans-4-amino-3-hydroxypiperidines with simple procedures.