Synthesis and Conformational Analysis of the First 3-Oxa-7-thia-1- r-azabicyclo[3.3.0]-c-5-octane Single Functionalised at the C-5 Position

Starting from TRIS [2-amino-2-(hydroxymethyl)propane-1,3-diol] via its thia analogue, 2-amino-2- (mercaptomethyl)propane-1,3-diol' double cyclocondensation with formaldehyde, we report a four steps synthesis of the first term in the title series of compounds, bearing the exploitable hydroxymethyl functionality at the C-5 position. Conformational analysis is discussed based on DFT calculations and 1H-DNMR.