Phenylacetylene → 6-(Phenylethynyl)-2',4',5',6'-tetrahydrospiro[chroman-2,3'-pyran]-4-one

HRID 1408830Notes

Reaction equation

Br[C:2]1[CH:3]=[C:4]2[C:14](=[CH:15][CH:16]=1)[O:13][C:7]1([CH2:12][CH2:11][CH2:10][O:9][CH2:8]1)[CH2:6][C:5]2=[O:17].[C:18]1([C:24]#[CH:25])[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1>[Cu]I.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1C=CC(P(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[C:18]1([C:24]#[C:25][C:2]2[CH:3]=[C:4]3[C:14](=[CH:15][CH:16]=2)[O:13][C:7]2([CH2:12][CH2:11][CH2:10][O:9][CH2:8]2)[CH2:6][C:5]3=[O:17])[CH:23]=[CH:22][CH:21]=[CH:20][CH:19]=1

Participants

Conditions

Temperature: 80 °C

Procedure

An oven dried 3-necked round bottom flask equipped with condenser was charged with 6-bromo-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (223 mg, 0.75 mmol), TEA (3 mL) and DEA (0.8 mL) under N2 atmosphere. To this solution was added CuI (5.7 mg, 0.03 mmol), PdCl2(PPh3)2 (21 mg, 0.03 mmol) and PPh3 (16 mg, 0.06 mmol). The system was degas once again, then phenylacetylene (0.41 mL, 3.75 mmol) was added and the mixture was heated to 80° C. (oil bath) with stirring. The reaction was evaporated after 12 h and the residue was purified by flash chromatography (12 g silica gel, eluted with EA in hexane in a gradient of 0-25%, v/v) to afford 6-(phenylethynyl)-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (216 mg, yield: 90%). MS ESI+ve m/z 319 (M+H)+.

Workup

customAn oven dried 3-necked round bottom flask
customequipped with condenser
customThe system was degas once again
customThe reaction was evaporated after 12 h
customthe residue was purified by flash chromatography (12 g silica gel
washeluted with EA in hexane in a gradient of 0-25%, v/v)

Sources & evidence

ORD record: ord-24ee20e742cc4097b960a1c704e3f71f
Source dataset: uspto-grants-2014_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08921359B2

Reaction notes

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