tert-butyl N-[(3S)-2-oxooxolan-3-yl]carbamate

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

Procedure: A mixture of N-tert-butoxycarbonyl-O-benzyl-L-homoserine methyl ester (A, 3.13 g) and 10% palladium on activated carbon (0.93 g) in methanol (160 mL) was stirred at room temperature for 14.5 hr under hydrogen. The catalysts were removed by filtration and washed with methanol. The combined organic layers were evaporated in vacuo. The residue was purified by silica gel column chromatography (chloroform:methanol=40:1 to 20:1, v/v) to afford the title compound (1.65 g) as a white powder: 1H NMR (400 MHz, CDCl3) δ 1.4-1.5 (m, 9H), 2.20 (m, 1H), 2.77 (m, 1H), 4.25 (m, 1H), 4.35 (m, 1H), 4.45 (t, J=8.8 Hz, 1H), 5.07 (m, 1H). The catalysts were removed by filtration washed with methanol The combined organic layers were evaporated in vacuo The residue was purified by silica gel column chromatography (chloroform

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

Procedure: A solution of 2-fluoro-4-iodoaniline (7.11 g) in anhydrous DCM (40 ml) under N2 at 0° C. was treated dropwise with trimethylaluminium (2N in heptane; 15 ml). The mixture was allowed to stir for 30 min before a solution of tert-butyl (3S)-2-oxotetrahydrofuran-3-ylcarbamate (5.03 g), in anhydrous DCM (35 ml), was added dropwise. The reaction was allowed to warm up to ambient temperature and stirred for 18 h, before quenching with 10% aqueous citric acid acid (10 ml) Saturated aqueous potassium sodium tartrate (100 ml) was then added with stirring followed by separation of the organic and aqueous layers. The organic layer was dried (over magnesium sulphate) and concentrated under reduced pressure. The residue was purified using Biotage™ chromatography (silica, eluting with cyclohexane:ethyl acetate 3:2) to afford an off-white solid which was an inseparable mixture (c. 1:2) of the starting material and the title compound (5.55 g). was added dropwise before quenching with 10% aqueous citric acid acid (10 ml) Saturated aqueous potassium sodium tartrate (100 ml) was then added with stirring followed by separation of the organic and aqueous layers The organic layer was dried (over magnesium sulphate) concentrated under reduced pressure The residue was purified Biotage™ chromatography (silica, eluting with cyclohexane:ethyl acetate 3:2) to afford an off-white solid which