Tetrahydrofuran → 4-Ethynyl-2-(methoxymethyl)furan

A mixture of partially purified 4-bromo-2-(methoxymethyl)furan (1.9 g) as obtained in Example 18-(2), AcOBu (16 mL), CuI (0.33 g), PdCl2(PPh3)2 (0.60 g), triisopropylsilylacetylene (9.6 mL) and TEA (12 mL) was stirred in a nitrogen atmosphere for 7.5 hours at 110° C. After the reaction mixture was allowed to cool, ethyl acetate (0.10 L), OH type silica gel (1.9 g), cellpure (0.95 g) and activated carbon (10 mg) were added. The insolubles were filtered out, and the filtrate was concentrated under reduced pressure. The resulting residue was purified by OH type silica gel column chromatography (gradient elution with hexane/ethyl acetate=100/0→80/20) to obtain a yellow oil (1.7 g). THF (4.0 mL) was added to this oil (0.80 g), and a 1 mol/L TBAF-THF solution (4.1 mL) was added dropwise to the mixture under ice cooling. The mixture was stirred for 30 minutes under ice cooling, and then stirred for 30 minutes at room temperature. The reaction mixture was concentrated under reduced pressure, and the resulting residue was purified by OH type silica gel column chromatography (gradient elution with hexane/ethyl acetate=100/0→90/10) to obtain 4-ethynyl-2-(methoxymethyl)furan (yellow oil) (0.24 g).

1. stirringstirred for 30 minutes at room temperature
2. concentrationThe reaction mixture was concentrated under reduced pressure
3. customthe resulting residue was purified by OH type silica gel column chromatography (gradient elution with hexane/ethyl acetate=100/0→90/10)

ORD record

ord-b076452293c84445ab64933f83fc7dae

Source dataset

uspto-grants-2015_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09073821B2