Reaction Steps
Acid (Example 95, step A. 4.01 g) was converted to tert-butyl 4-[(1S)-1-azido-2-oxo-2-(1,3-thiazolidin-3-yl)ethyl]piperidine-1-carboxylate (1.3 g) in 4 steps using the procedures outlined in Example 6. 1H NMR (500 MHz, CD3OD, HCl salt) δ 4.71–4.49 (m, 2H), 4.09 (bs, 2H), 3.98–3.74 (m, 2H), 3.42 (d, 0.4H, J=7 Hz), 3.40 (d, 0.6H, J=7 Hz), 3.18 (t, 1.2H, J=5.6 Hz), 3.02 (t, 0.8H, J=5.6 Hz), 2.72 (bs, 2H), 2.18 (m, 1H), 1.99 (d, 1H, J=13 Hz), 1.61 (d, 1H, J=13.5 Hz), 1.42 (s, 9H), 1.24 (m, 1H), 1.19 (m, 1H). A portion of this material (30 mg) was dissolved in wet THF and triphenyl phosphine (26 mg) was added to the solution. The mixture was heated at 60° C. for 5 h, cooled, concentrated and purified by preparative TLC on silica gel (eluent: 5 to 10% methanol in CH2Cl2) to give the title compound. 1H NMR (500 MHz, CDCl3) δ 4.68–4.48 (m, 2H), 4.18 (bs, 2H), 3.99–3.69 (m, 2H), 3.36 (d, 0.4H, J=7 Hz), 3.29 (d, 0.6H, J=7 Hz). 3.1 (t, 1.2H, J=5.6 Hz), 3.0 (t, 0.8H, J=5.6 Hz), 2.61 (bs, 2H), 1.92 (bd, 1H, J=13.5 Hz), 1.65 (m, 1H), 1.58 (m, 1H), 1.42 (s, 9H), 1.25 (m, 1H), 1.20 (m, 1H).
