反応 #430108
ord-064ba804b8c14917ab721826a3e2fe6b
反応物
試薬
反応条件
後処理
- 1その他proceeded to completion over the course of about one and half hours at room temperature
- 2その他the phases were separated
- 3抽出the aqueous phase extracted with ethyl acetate (3×15 mL)
- 4洗浄The combined organic extracts were washed with brine
- 5乾燥dried over MgSO4
- 6濃縮the solvent concentrated
- 7その他to give the crude product, which
実験手順
To a stirred solution of (DHQ)2 -PHAL (0.11 g, 0.14 mmol, 5 mol %) in 20 mL of acetonitrile and 20 mL of water, in any convenient-sized glass vessel or vial, was added desired acrylate or methacrylates entries 1-10 (all commercially available from Aldrich, FIG. 16 and FIG. 17, 2.8 mmol), Chloramine-T trihydrate (2.42 g, 8.4 mmol, 3 eq) and K2OsO2 (OH)4 (41.6 mg, 0.112 mmol, 4 mol %). As the reaction proceeded to completion over the course of about one and half hours at room temperature, the color of the solution changed from yellow to pale green, then deep green and finally back to yellow. After addition of aqueous sodium sulfite (1.0 g in 15 mL H2O), the phases were separated, and the aqueous phase extracted with ethyl acetate (3×15 mL). The combined organic extracts were washed with brine, dried over MgSO4 and the solvent concentrated to give the crude product, which also contains the p-toluenesulfonamide by-product produced upon the reduction of the excess Chloramine-T. Purification provides compounds as shown in FIG. 16, entries 1-10 with the indicated yields and conditions. NOTE: Replacement of the 3 eq of Chloramine-T with 1.5 eq of Chloramine-T and 1.5 eq of Et4NOAc gives comparable results and reduces the amount of p-toluenesulfonamide by-product formed. This can greatly simplify product isolation, especially in cases where the product and the toluenesulfonamide have similar chromatographic mobilities. ##STR17##