To a solution of 2 (100 mg, 0.239 mmol) in dimethylsulfoxide (2.40 mL), NaH2PO4 (66.0 mg, 0.478 mmol), dissolved in water (0.960 mL), was added dropwise at room temperature. The mixture was then kept on ice and NaClO2 (86.0 mg, 0.956 mmol) dissolved in water (0.480 mL), was added dropwise during 30 min. A white precipitate formed. The reaction mixture was stirred in room temperature for 1 h and then poured into a separation funnel containing ice-cooled 1M HCl. The aqueous phase was extracted with CH2Cl2 and the combined organic phases concentrated. The residue was dissolved in H2O:MeCN, 8:2 and freeze dried to yield 5 as a white powder (102 mg, yield: 98%). 1H-NMR (400 Mhz, CDCl3) δ 14.60 (s, 1H, CO2H), 8.21 (d, J=8.32 Hz, 1H, ArH), 7.85 (d, J=7.68 Hz 1H, ArH), 7.67 (d, J=8.14 Hz, 1H, ArH) 7.61-7.45 (m, 2H, ArH) 7.30-7.21 (m, 1H, ArH), 6.69 (d, J=6.72 Hz, 1H, ArH), 5.78 (d, J=8.42 Hz, 1H, ArH), 5.51 (d, J=14.55 Hz, 1H, Nph-CH2) 5.37 (d, J=14.55 Hz, 1H, Nph-CH2) 3.87 (s, 3H, CH3) 3.82-3.72 (m, 1H, SCH2) 3.63-3.54 (m, 1H, SCH2) 1.44-1.32 (m, 1H, CH-cyclopropyl) 0.81-0.64 (m, 2H) 0.56 (sd, 2H, CH2-cyclopropyl) 13C-NMR (100 Mhz, CDCl3) δ 167.59, 165.24, 165.09, 163.75, 154.33, 134.92, 133.84, 132.16, 128.83, 126.78, 126.15, 125.76, 125.51, 123.40, 123.23, 118.68, 112.72, 64.10, 53.84, 33.35, 31.58, 12.10, 8.35, 7.67.
