Hydrogen Peroxide → HCID 131718263, compound

Participants

Reaction Steps

To a solution of borane in THF (1.44 mL of a 1M solution, 1.44 mmol) at 0° C. under nitrogen, was added cyclohexene (0.29 mL, 2.88 mmol) by syringe, and the mixture was stirred for 0.5 hour, during which time a white precipitate formed. A prechilled (0° C.) solution of t-BOC-Asp(OBn)-α-allylphenylalaninamide (480 mg, 0.92 mmol), from Step e, in anhydrous THF (4 mL) was added and stirring was continued for 2 hours at 0° C., then at ambient temperature overnight. The solution was diluted with pH 7 buffer and ethanol and treated with excess 30% aqueous H2O2 and stirred overnight. The reaction mixture was then partitioned between ethyl acetate and brine and the aqueous phase was extracted with two portions of ethyl acetate. The ethyl acetate solutions were combined, dried over anhydrous sodium sufate, filtered and concentrated. The residue (514 mg) was chromatographed on silica gel eluting with hexane/acetone (1:1) to give 266 mg (54% yield) of the title compound (1:1 diastereomeric mixture) as a colorless solid, m.p. 75°-79° C.; 1H NMR (CDCl3) δ1.37 (s) and 1.40 (s) (total of 9H), 1.50-1.71 (m,2H), 1.92-2.12 (m) and 2.13-2.27 (m) (total 2H), 2.21-2.38 (overlapping dd's,J=6 and 18 Hz and J=5 and 16 Hz,total 2H), 3.10 (dd,J=4.5 and 17 Hz,2H), 3.25-3.48 (m,2H), 3.61 (m,2H), 4.60 (m,1H), 5.10 (s) and 5.12 (s) (total 2H), 5.32 (br m,1H), 5.45 (br t,J=9 Hz,1H), 6.42 (br m,1H), 7.12 (m,2H), 7.16-7.40 (m,8H). MS (DCl/NH3) m/e 528 (M+H)+, 545 (M+NH4)+ . Analysis calculated for C28H37N3O7.0.1H2O: C, 63.52; H, 7.08; N, 7.94. Found: C, 63.21; H, 7.03; N, 7.68.

Provenance & Evidence