... Tetrahedron Letters. Volume 54, Issue 11, 13 March 2013, Pages 1449–1451. ... 11 and 12 The reaction was initially performed at a substrate to catalyst mole ratio (S/C) of 400 in MeOH under 8 atm of H 2 at 70 °C for 24 h (Table 1). With catalyst (R a ,R)-1a, the hydrogenation ...