Dichloromethane → HCID 86713137, compound

Participants

Reaction Conditions

Reaction Steps

Under argon, ethyl (2Z)-3-[(8-hydroxy-2,3,7,9,9-pentamethyl-1,4-dioxaspiro[4.5]dec-6-en-8-yl)ethynyl]-hex-2-enoate (340 mg, 0.87 mmol) was dissolved in a round-bottom flask in abs. dichloromethane (4 ml), and triethoxysilane (172 mg, 1.05 mmol) was added. The reaction solution was then cooled to 0° C., tris(acetonitrile)cyclopentadienylruthenium(II) hexafluorophosphate (18 mg, 0.04 mmol) was added and the mixture was stirred at room temperature for 2 h. Diethyl ether was then added, and the reaction mixture was concentrated under reduced pressure. The residue that remained was dissolved in abs. tetrahydrofuran (4 ml), copper(I) iodide (16 mg, 0.09 mmol) and tetra-n-butylammonium fluoride (289 mg, 1.11 mmol) were added, the mixture was stirred at room temperature for 4 h, and water was then added. The aqueous phase was repeatedly extracted thoroughly with dichloromethane. The combined organic phases were then dried over magnesium sulfate, filtered and concentrated under reduced pressure. Purification of the resulting crude product by column chromatography (ethyl acetate/heptane gradient) gave ethyl (2Z)-3-[(E)-2-(8-hydroxy-2,3,7,9,9-pentamethyl-1,4-dioxaspiro[4.5]-dec-6-en-8-yl)vinyl]hex-2-enoate (140 mg, 41% of theory) in the form of a colorless oil. 1H-NMR (400 MHz, CDCl3 δ, ppm) 7.68 (d, 1H), 6.09 (d, 1H), 5.97 (s, 1H), 5.48 (s, 1H), 4.19 (m, 3H), 3.61 (m, 1H), 2.29 (m, 1H), 2.22 (m, 2H), 2.02 (m, 1H), 1.92 (m, 3H), 1.67 (m, 2H), 1.62 (m, 1H), 1.28 (m, 6H), 1.20-1.08 (m, 9H), 0.91 (t, 3H).

Provenance & Evidence