Ammonia → Butanedioic acid, 1,4-di-2-propen-1-yl ester

Participants

Reaction Steps

11 (240 mg, 0.46 mmol) and HATU (350 mg, 0.92 mmol) were dissolved in DMF (2 mL) and diisopropylethylamine (0.16 mL, 0.92 mmol) was added. The mixture was stirred for 15 min at ambient temperature, and then treated with anhydrous ammonia for 20 min. Stirring was continued overnight. DMF was removed in vacuo, and the residue was diluted with ethyl acetate, washed with water and brine, then dried over MgSO4. After evaporation of the solvent, the residue was purified on silica gel (5% methanol/methylene chloride) to afford product 12 as a white solid. 12, a mixture of two diastereomers, was then separated on silica gel, using increasing gradient of 20-50% ethyl acetate-methylene chloride, to give first eluting isomer 12a (43 mg, 18%.) and the second eluting isomer 12b (61 mg, 25%) both as a white solids. 12a: MS m/z 521.2 (MH+). 12b: MS m/z 521.2 (MH+).

Provenance & Evidence