Sodium Thiosulfate → 3-Flavanone

To a hazy suspension of Dess Martin periodinane (1 g, 2.295 mmol) in dry methylene chloride (10 mL) was added a solution of trans 3-flavanol 6 (0.8 g, 1.53 mmol) in methylene chloride (10 mL) at room temperature. The resulting purple solution was stirred at room temperature for 4 h, after which it was poured into a saturated solution of sodium bicarbonate (60 mL) containing 7 equivalents of sodium thiosulfate (16.06 mmol, 3.98 g) and stirred for 10 minutes. The resulting brown solution was extracted with methylene chloride and the organic layer washed with water and brine, and dried (MgSO4). The filtered solution was then evaporated to afford the crude 3-flavanone 7, which was purified by flash chromatography, using hexanes: ethyl acetate (95:5 to 8:2) to afford 0.432 g (53%) of pure product as a thick, colorless oil. TLC: hexanes: methylene chloride: ethyl acetate (3:1:1): Rf=0.39; 1H NMR (300 MHz, CDCl3): δ 3.60 (dd, 2H, 4-Hα and β), 3.79 (s, 6H, OCH3), 3.82 (s, 3H, OCH3), 5.02 (s, 2H, OCH2Ph), 5.04 (s, 2H, OCH2Ph), 5.29 (s, 1H, 2-H), 6.32 and 6.41 (2d, 2H, 6, 8-Ar—H), 6.58 (s, 2H, 2′,6′-Ar—H), 7.37–7.40 (m, 10H, Ar—H).

1. stirringstirred for 10 minutes
2. extractionThe resulting brown solution was extracted with methylene chloride
3. washthe organic layer washed with water and brine
4. dry with materialdried (MgSO4)
5. customThe filtered solution was then evaporated
6. customto afford the crude 3-flavanone 7, which
7. customwas purified by flash chromatography

ORD record

ord-fbded7428ac4434c88cffcee707bf46f

Source dataset

uspto-grants-2006_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07109236B2