Participants
| Role | Name | HCID | Charge |
|---|
| Reactant | Water | HCID 962 | — |
| Reactant | Boron trifluoride etherate | HCID 8000 | — |
| Reactant | Trimethylsilyl cyanide | HCID 82115 | — |
| Reactant | HCID 15711862 | HCID 15711862 | — |
| Solvent | Dichloromethane | HCID 6344 | — |
| Product | HCID 15711866 | HCID 15711866 | 92% |
Reaction Steps
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.
Provenance & Evidence
| DOI | 10.6084/m9.figshare.5104873.v1 |
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| Patent number | US04994486 |
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| Source dataset | uspto-grants-1991_02 |
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| ORD ID | ord-dc2beed0fd8140788c4139f8098cdd07 |
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| Source note | uspto-grants-1991_02 |
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