680596-79-6

1,4-Dioxaspiro[4.5]dec-7-en-8-yl trifluoromethanesulfonate (500 mg, 1.73 mmol) and pinacol bis(boronic acid) ester (530 mg, 2.08 mmol) were used as the raw materials, and 1,4-dioxane (8 mL) was used as the solvent under nitrogen protection, and potassium acetate (260 mg, 2.64 mmol) and Pd(dppf) Cl2 (130 mg, 0.17 mmol). The reaction mixture was stirred at 110 °C for 10 hours. After completion of the reaction, the insoluble material was removed by filtration, and the filtrate was concentrated under reduced pressure and purified by column chromatography (eluent: petroleum ether/ethyl acetate, v/v=2/1) to afford 540 mg of the yellow oily product 1,4-dioxa-spiro[4,5]dec-7-ene-8-boronic acid pinacol ester in 99% yield.

[1] Patent: CN106336413, 2017, A. Location in patent: Paragraph 0431; 0432; 0433
[2] Patent: US2010/56576, 2010, A1. Location in patent: Page/Page column 20
[3] Patent: US2008/300242, 2008, A1. Location in patent: Page/Page column 102
[4] Patent: WO2017/192811, 2017, A1. Location in patent: Paragraph 00173
[5] Bioorganic and Medicinal Chemistry Letters, 2014, vol. 24, # 23, p. 5377 - 5380