Pyridine N-Oxide → Benzopyran

Temperature

0 °C

26.2 mg of compound [IV-1] (0.10 mmol) and 2.6 mg of the compound [I-1] (2.5 μmol) were dissolved in 1.25 mL of an acetonitrile solution of pyridine-N-oxide (0.02M, 0,025 mmol), followed by cooling to 0° C. To the resulting solution was added 44.0 mg of iodosylbenzene (0.20 mmol) all at once under a nitrogen atmosphere, followed by stirring at 0° C. for twenty four hours. Insoluble matters were filtered out through Celite, the filtrate was concentrated, and the residues were purified by silica gel column chromatography (eluent: hexane-ethyl acetate=8:2-4:6) to obtain the intended compound. (epoxide yield: 20. 1 mg (72%)) (asymmetric yield: 98% e.e.) (Daicel Chiralcel OJ, hexane-isopropanol=1:1, flow rate: 0.5 mL/min.)

1. filtrationInsoluble matters were filtered out through Celite
2. concentrationthe filtrate was concentrated
3. customthe residues were purified by silica gel column chromatography (eluent: hexane-ethyl acetate=8:2-4:6)
4. customto obtain the intended compound

ORD record

ord-2e9b66f86c354495b91954abdfbed2ef

Source dataset

uspto-grants-1995_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05420314