tert-Butanol → tert-butyl(1S,2S,4S)-1-benzyl-4-[(tert-butoxycarbonyl)amino]-2-hydroxy-5-[4-(2-pyridinyl)phenyl]pentylcarbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of the product from Example 1B (7.32 g, 12.1 mmol) in toluene (400 mL) were treated with DPPA (5.2 mL, 24.2 mmol) and triethylamine (3.4 mL, 24.4 mmol), heated at reflux for 2 hours, cooled, treated with tert-Butyl alcohol (41.6 mL), triethylamine (4 mL), and DMAP (0.30 g), heated at reflux for an additional 64 hours, cooled and concentrated. A solution of the residue in THF (60 mL) was treated with TBAF solution in THF (36 mL, 1N), stirred at 25° C. for 40 hours, concentrated and partitioned between ethyl acetate and water. The organic phase was washed with brined, dried over MgSO4, filtered and concentrated. The residue was chromatographed on silica gel eluting with 0-50% ethyl acetate in dichloromethane to give 0.614 g (9% yield) of the lower Rf product by TLC (25% ethyl acetate in dichloromethane).

Provenance & Evidence