反应详情

Daunomycinone (IX) (10 mg, 0.025 mmole) was placed in CHCl3 (1 ml). Br2 (13.5 mg) in CHCl3 (0.25 ml) was added and the solution stirred at 23° for 16 hrs. The solvent was removed and the residue was dissolved in 80% aq acetone (5 ml). NaOH (1.1 mg. 0.028 mmole) was added and the blue solution was refluxed for 5 min when the red color returned. The solution was concentrated to approximately 2 ml, diluted with water (10 ml) and extracted with 50% CHCl3 /MeOH (3 × 10 ml). The extracts were combined, dried and evaporated. The residue was crystallized from CHCl3 -MeOH/pet. ether (30°-60°) to afford 9.0 mg (87%) of (XI): irnujol 2.85 (OH), 5.75 (C = O), 615, 628 μ (chelated quinone); pmr 100 MHz CDCl3 δ 2.0-2.5 (m, 2H, 8-H2), 2.8-3.2 (m, 2H, 10-H2), 3.43 (m, 1H, 9-OH), 4.09 (s, 3H, OMe), 4.70 (d, 2H, J = 16Hz, 14-H2), 5.34 (m, 1H, ∥1/2 = 8Hz, 7-H), 7.38 (dd, 1H, J = 8Hz and J = 1Hz, 3-H), 7.76 (t, 1H, J = 8Hz, 2-H), 8.00 (dd, 1H, J = 8Hz and J = 1Hz, 1-H), 13.24 (s, 1H, 6-OH), 13.99 (s, 1H, 11-OH).

1. customThe solvent was removed
2. dissolutionthe residue was dissolved in 80% aq acetone (5 ml)
3. temperaturethe blue solution was refluxed for 5 min when the red color
4. concentrationThe solution was concentrated to approximately 2 ml
5. additiondiluted with water (10 ml)
6. extractionextracted with 50% CHCl3 /MeOH (3 × 10 ml)
7. customdried
8. customevaporated
9. customThe residue was crystallized from CHCl3 -MeOH/pet. ether (30°-60°)