methyl 3-iodo-2-[(2-methylpropan-2-yl)oxycarbonylamino]propanoate

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a three necked flask charged with zinc dust (2.23 g, 34.1 mmol) under an N2 atmosphere DMF (13 mL) was added. The suspension was efficiently stirred and I2 (0.20 g, 0.80 mmol) was added. ((S)-2-[(tert-Butoxycarbonyl)amino]-3-iodopropionic acid methyl ester (4.50 g, 13.7 mmol) was added in one portion, and immediately after more I2 (0.20 g, 0.80 mmol) and the stirring was continued for 2 h. Negishi coupling was then effected by addition in direct sequence of: Pd2 dba3 (315 mg, 0.34 mmol), 2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl (279 mg, 0.68 mmol), and 1-bromocyclopentene (2.32 g, 15.8 mmol) in DMF (4 mL). The reaction was stirred over night. DCM (25 mL) was added and the mixture was filtered, the solids were washed with further DCM, water (30 mL) was added and the phases were separated. The aqueous phase was extracted with DCM (2×20 mL) and the combined organic phases were washed with H2O (20 mL), dried MgSO4, filtered and evaporated. The residue was purified by gradient silica gel chromatography (4-16% EtOAc in iso-hexane) which gave the title compound 1.24 g (30%). GC-MS EI m/z 213 (w), 196 (w), 152, 88, 57, 41. was added The reaction was stirred over night the mixture was filtered the solids were washed with further DCM, water (30 mL) was added the phases were separated The aqueous phase was extracted with DCM (2×20 mL) the combined organic phases were washed with H2O (20 mL), dried MgSO4 filtered evaporated The residue was purified by gradient silica gel chromatography (4-16% EtOAc in iso-hexane) which

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of zinc dust (300 mg) in dimethylacetamide (DMA) (0.3 mL) at 50° C. was treated with a solution of chlorotrimethylsilane/1,2-dibromoethane (7/5 v/v, 0.04 mL) and the reaction was stirred at room temperature for 30 minutes. A solution of methyl 2-(tert-butoxycarbonylamino)-3-iodopropanoate (247 mg, 0.75 mmol) in DMA (1 mL) was slowly added and the reaction was stirred for 40 minutes. This mixture was added to a mixture of 95G (35 mg), PdCl2(dppf)2 (7 mg), and CuI (10 mg) in DMA (0.8 mL). The reaction was heated to 80° C. for 18 hours. Water was added and the solid precipitate was collected by filtration. The solid was treated with 33% HBr/AcOH and then concentrate. The residue was dissolved in THF/MeOH and water and treated with LiOH and stirred at room temperature for two hours. The reaction mixture was neutralized with trifluoroacetic acid and purified by preparative reversed phase HPLC to afford the desired product (1.7 mg). Compound 103 had an analytical HPLC retention time=2.906 min. (Chromolith SpeedROD column 4.6×50 mm, 10-90% aqueous methanol over 4 minutes containing 0.1% TFA, 4 ml/min, monitoring at 220 nm) and a LC/MS M++1=528+. the reaction was stirred for 40 minutes The reaction was heated to 80° C. for 18 hours the solid precipitate was collected by filtration The solid was treated with 33% HBr/AcOH concentrate The residue was dissolved in THF/MeOH water and treated with LiOH stirred at room temperature for two hours purified by preparative reversed phase HPLC