Synthesis of (2S,3R)- and (2S,3S)-[3-2H1]-proline via highly stereoselective hydrolysis of a silyl enol ether

Abstract A straightforward synthesis of (2 S )-[3,3- 2 H 2 ]-proline 1c and (2 S ,3 R )- and (2 S ,3 S )-[3- 2 H 1 ]-proline, 1b and 1a , respectively, has been devised. The key step of the route to the latter compounds involves highly stereoselective hydrolysis of the silyl enol ethers 3 and 3a , respectively, with protonation (deuteriation) from the re -face of the silyl enol ether.