[CH3:1][O:2][C:3]([CH2:5]P(OC)(OC)=O)=[O:4].[Cl-].[Li+].N12CCCN=C1CCCCC2.[OH:25][C:26]1[CH:27]=[C:28]([CH:31]=[CH:32][CH:33]=1)[CH:29]=O>C(#N)C.O>[CH3:1][O:2][C:3](=[O:4])/[CH:5]=[CH:29]/[C:28]1[CH:31]=[CH:32][CH:33]=[C:26]([OH:25])[CH:27]=1A solution of trimethyl phosphonoacetate (9.94 mL, 61.4 mmol), lithium chloride (2.60 g, 12.2 mmol) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) (15.92 mL, 106.5 mmol) in acetonitrile (80 mL) at room temperature under a nitrogen atmosphere was stirred at room temperature for 30 minutes. 3-Hydroxybenzaldehyde (5.00 g, 40.9 mmol) was added, and the mixture was stirred at room temperature for an additional 3 hours. Water was added and the aqueous phase was extracted with diethyl ether. The combined organic fractions were washed with water, brine, dried over magnesium sulfate, and evaporated to dryness. Purification by flash chromatography, eluting with hexane/ethyl acetate, gave trans-3-(3-hydroxyphenyl)acrylic acid methyl ester as a white crystalline solid (6.30 g, 86%).
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