N-TFA-Gly-Bt-Based Stereoselective Synthesis of Substituted 3-Amino Tetrahydro-2H-pyran-2-ones via an Organocatalyzed Cascade Process

Chiral-substituted 3-amino tetrahydro-2H-pyran-2-ones were prepared in excellent enantioselectivities (up to 99% ee) via an organo-catalyzed cascade procedure with N-TFA-Gly-Bt and alpha,beta-unsaturated aldehydes as the substrates. The corresponding tetrahydro-2H-pyran-2-ones can be used for further synthetic transformations that furnish chiral-substituted 3-aminopiperidin-2-ones with high levels of stereoselectivity.