6-Carbomethoxymethyl-6-ethyl-2-cyclohexen-1-one → HCID 23324905, compound

Participants

Reaction Steps

Following the procedure of Paquette et al., J. Am. Chem. Soc., 103, 1831 (1981) a solution of cyclopentylmagnesium bromide (222.5 mmol, 111.2 ml of 2M in Et2O), in 481 ml of dry THF under nitrogen was cooled to -78° C. and treated dropwise with a solution of 120.4 mmol (24.75 g) of CuBr.Me2S in 170 ml of Me2S. After 1.5 hours at -78° C., a solution of the enone, 6-carbomethoxymethyl-6-ethyl-2-cyclohexene-1-one prepared in Example 1, Step (c), (40.77 mmol, 8 g) in 80 ml of THF was added dropwise. After 1.5 hours, TLC indicated the consumption of enone and the reaction was quenched with 250 ml of 1M HCl (aq.) and extracted with 2×100 ml of CH2Cl2 and 2×100 ml of petroleum ether. Drying (Na2SO4) and flash chromatography afforded 8.027 g (30.13 mmol, 74%) of pale yellow oil containing a mixture of diastereomers. This material was combined with another batch to give 11.04 g and this was separated by preparative HPLC to afford 2.96 g of a less polar isomer and 4.3 g of a more polar isomer.

Provenance & Evidence