Water → HCID 15711866, compound

Temperature

-78 °C

A solution of 9.07 g (31.7 mmol) of 3,4-dihydro -1-hydroxy-5-methoxymethoxy-3-phenyl-1H-2-benzopyran, from Step 2 above, in 150 mL of methylene chloride at -78° C. was treated, sequentially, with trimethylsilyl cyanide (8.5 mL, 64 mmol) and boron trifluoride etherate (6 mL, 49 mmol). After being stirred for 1.5 h at -78° C., and for 4 h at ambient temperature, 100 mL of water was added and stirring was continued for 1 h. The reaction mixture was then extracted with 2×300 mL of ethyl acetate and the combined organic extract was washed with 200 mL of brine, dried over anhydrous sodium sulfate, filtered and concentrated in vacuo. The residue was purified on silica gel eluted with 10% ethyl acetate in hexane to give 7.33 g (92% yield) of the title compound as a 4:1 mixture of the trans and cis isomers.

1. waitfor 4 h at ambient temperature
2. stirringstirring
3. waitwas continued for 1 h
4. extractionThe reaction mixture was then extracted with 2×300 mL of ethyl acetate
5. extractionthe combined organic extract
6. washwas washed with 200 mL of brine
7. dry with materialdried over anhydrous sodium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customThe residue was purified on silica gel
11. washeluted with 10% ethyl acetate in hexane

ORD record

ord-dc2beed0fd8140788c4139f8098cdd07

Source dataset

uspto-grants-1991_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04994486