4720-83-6

6-Oxabicyclo[3.2.1]oct-3-en-7-one is used in the convergent total synthesis of Leustroducsin B.

General procedure for the synthesis of 6-oxabicyclo[3.2.1]oct-3-en-7-one from 4-iodo-3-cyclohexanecarboxylic acid lactone: to a solution of 4-iodo-6-oxabicyclo[3.2.1]octan-1-one (8.00 g, 31.7 mmol) in benzene (100 ml), 1,8-diazabicyclo[5.4.0]undec-7-ene (7.9 g, 32 mmol). The mixture was heated to reflux for 6 hours under nitrogen protection. After completion of the reaction, the reaction solution was cooled, the white precipitate was collected by filtration and washed with ether (100 ml). The filtrates were combined and washed sequentially with water (50 ml), 1N HCl (50 ml) and brine (25 ml) and then dried with magnesium sulfate. The solvent was removed by rotary evaporation to afford the target product olefin as a light brown oil (2.6 g, 66% yield).

[1] Patent: WO2005/37832, 2005, A2. Location in patent: Page/Page column 67
[2] Journal of the American Chemical Society, 2010, vol. 132, # 35, p. 12179 - 12181
[3] Patent: WO2014/70991, 2014, A2. Location in patent: Page/Page column 68
[4] Patent: WO2015/48616, 2015, A1. Location in patent: Paragraph 00128