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

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Reaction Conditions

Reaction Steps

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)+.

Provenance & Evidence