Sulfuric Acid → HCID 13294648, compound

Participants

Reaction Steps

Into a 2000 L reactor was charged acetone (1200 L) and 2,2-dimethoxypropane (125 kg, 1200 mol, 1.2 eq), followed by D-ribose (150 kg, 999 mol). The mixture was stirred at ambient temperature. p-TSA (p-toluene sulfonic acid) (9.6 kg, 49.5 mol, 0.05 eq) was added in portions over 40 minutes. The reaction mixture was heated at 30° C. and monitored by TLC every hour. After 14 hours, TLC indicated complete conversion. A sample from the reaction mixture and standard samples for ribose and ribose acetonide were applied to a commercial silica gel TLC plate, and the plate was run in the mobile phase dichloromethane/ethanol=8:1. The plate was then sprayed with 10% H2SO4 in ethanol and heated using a heat gun. Ribose-related compounds gave dark spots on the plate. The Rf for Ribose was ˜0.1, while Rf for ribose acetonide (1) was usually 0.3˜0.35. To the reaction mixture was added triethylamine (8.1 kg, 0.08 eq). Acetone was distilled under vacuum (water bath temperature<60° C.) over 12 hours. The residue was diluted with dichloromethane (300 L). The mixture was stirred for 0.5 hour at ambient temperature, and then solvent was removed under vacuum over 4 hours. This operation was repeated once, and the residue was used in next step without further purification. 1H NMR (400 MHz, CD3OD) δ 1.31 (s, 3H, CH3), 1.44 (s, 3H, CH3), 3.59 (dd, J=5.6, 12.0 Hz, 1H, HOCHH), 3.63 (dd, J=4.8, 12.0 Hz, 1H, HOCHH), 4.19 (irregular t, J=4.4, 5.2 Hz, 1H, 4-H), 4.52 (d, J=6.0 Hz, 1H, 3-H), 4.77 (d, J=6.0 Hz, 1H, 2-H), 5.26 (s, 1H, anomeric H). Anal. calcd for C8H14O5: C, 50.52; H, 7.42. Found: C, 50.48; H, 7.36; [α]25D−36.2 (c 1.45, acetone) [lit., [α]25D−37 (c 0.53, acetone)].

Provenance & Evidence