3-Cyclopentene-1-carboxylic acid → 2-Phenylpropan-2-yl cyclopent-3-enecarboxylate

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Reaction Steps

A solution of 2-phenylpropan-2-yl 2,2,2-trichloroacetimidate (23.85 g, 85 mmol) in cyclohexane (85 mL) was treated with a solution of cyclopent-3-enecarboxylic acid (4.77 g, 42.5 mmol) in methylene chloride (43 mL), and the mixture was stirred for about 16 hours at room temperature during which time a colorless solid precipitated. The precipitate was collected by filtration and rinsed with hexanes. The combined filtrates were concentrated in vacuo to yield a residue. The residue was purified over a 330 g silica gel column, eluting at 100 mL/min with a 0-5% ethyl acetate/hexanes gradient over 2 column volumes, then 5% ethyl acetate/hexanes for 2 column volumes, then a 5-40% ethyl acetate/hexanes gradient over 10 column volumes to yield 2-phenylpropan-2-yl cyclopent-3-enecarboxylate (8.84 g, 38.4 mmol, 90% yield) as a yellow oil.

Provenance & Evidence