Methanesulfonyl chloride → 1-[5-O-Benzoyl-2-deoxy-4-ethynyl-3-O-methanesulfonyl-beta-D-threo-pentofuranosyl]thymine

Participants

Reaction Steps

To a pyridine (3.5 mL) solution of 4 (110.9 mg, 0.30 mmol) was added MsCl (0.12 mL, 1.5 mmol) at 0° C. under Ar atmosphere, and the mixture was stirred for 6 h. The reaction mixture was partitioned between CHCl3/sat. aqueous NaHCO3. Silica gel column chromatography (1.5% MeOH in CH2Cl2) of the organic layer gave 5 (105.2 mg, 78%) as a foam: 1H NMR (CDCl3) δ1.92 (3H, d, JMe,6=1.2 Hz, Me-5), 2.43 (1H, dd, J1′,2′a=3.6 and J2′a,2′b=16.0 Hz, H-2′a), 2.72 (1H, s, C≡CH), 3.07 (3H, s, SO2Me), 3.23 (1H, ddd, J1′,2′b=8.2, J2′b,3′=5.2 and J2′a,2′b=16.0 Hz, H-2′b), 4.72 (1H, d, J5′a,5′b=11.2 Hz), 4.76 (1H, d, J5′a,5′b=11.2 Hz), 5.37 (1H, d, J2′b,3′=5.2 Hz, H-3′), 6.56 (1H, d, J1′,2′a=3.6 and J1′,2′b=98.2 Hz, H-1′), 7.36 (1H, d, JMe,6=1.2 Hz), 7.47-7.51, 7.60-7.64 and 8.07-8.10 (5H, each as m, Ph), 8.32 (1H, br); FAB-MS (m/z) 449 (M++H).

Provenance & Evidence