benzyloxycarbonyl-L-valyl-L-proline t-butyl ester → Z-Val-pro-OH

Participants

Reaction Steps

A solution of N-benzyloxycarbonyl-L-valyl-L-proline tert-butyl ester (20 g) in methanol (300 ml) was hydrogenated at 50 psi over 10% palladium on carbon catalyst (2 g) for 12 hours. The reaction mixture was then filtered through diatomaceous earth and the filter cake washed with methanol. The filtrate was evaporated to give L-valyl-L-proline tert-butyl ester (A) (12 g) as an oil; NMR (300 MHz, d6 -DMSO): 0.80 (d, 3H), 0.92 (d, 3H), 1.74 (s, 9H), 1.79-2.15 (m, 5H), 3.22 (d, 1H), 3.30 (bs, 2H), 3.40 (m, 1H), 3.62 (m, 1H), 4.16 (dd, 1H).

Provenance & Evidence