4.1.23  N-{[(4R,6R)-6-(6-amino-9H-purin-9-yl)-2,2-dimethyl-tetrahydro-2H-furo[3,4-d] [1,3]dioxol-4-yl]methyl}-2-methoxy-4-nitrobenzene-1-sulfonamide (27)
Following method A with 5′-amino-2′,3′-isopropylidene adenosine (280 mg, 0.92 mmol, 1.00 eq) and 2-methoxy-4-nitrobenzenesufonyl chloride, 27 (200 mg, 42%) was obtained as a beige solid. Rf 0.59 (8:92 MeOH/DCM). 1H NMR (600 MHz, DMSO‑d 6) δ 8.30 (t, J = 5.4 Hz, 1H), 8.23 (s, 1H), 8.12 (s, 1H), 7.88–7.82 (m, 2H), 7.77 (dd, J = 8.5 Hz, J = 2.2 Hz, 1H), 7.37 (br. s, 2H), 6.06 (d, J = 2.9 Hz, 1H), 5.31 (dd, J = 6.3 Hz, J = 3.0 Hz, 1H), 4.90 (dd, J = 6.4 Hz, J = 2.9 Hz, 1H), 4.16 (td, J = 5.7 Hz, J = 2.9 Hz, 1H), 3.88 (s, 3H), 3.24–3.12 (m, 2H), 1.49 (s, 3H), 1.27 (s, 3H). 13C NMR (150 MHz, DMSO‑d 6) δ 156.7, 156.2, 152.6, 150.8, 148.3, 140.1, 133.5, 130.3, 119.3, 114.8, 113.4, 107.7, 89.5, 84.2, 82.9, 81.5, 56.8, 44.7, 26.9, 25.1. HRMS (ESI+): m/z calcd for C20H24N7O8S [M+H]+: 522.1407, Found 522.1407.