18-Crown-6 → HCID 44119788, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 18-crown-6 (17 g, 64 mmol) and bis(2,2,2-trifluoroethyl)(methoxycarbonylmethyl)phosphonate (4.5 g, 14 mmol) in 200 mL of THF was added potassium bis(trimethylsilyl)amide (31 mL of 0.5M THF solution, 15.5 mmol). After 15 min a solution of 3-cyclopentoxy-4-methoxybenzaldehyde (2.8 g, 13 mmol) in 5 mL of THF was then added dropwise. The resulting solution was stirred at -78° C. for 30 min and quenched with sat NH4Cl. The mixture was diluted with ether and washed with 1M H3PO4, H2O, and brine. The organic layer was dried over MgSO4, filtered, and concentrated under reduced pressure. Silica gel chromatography (3:1, hexanes:ethyl acetate) provided (Z)-methyl-3-(3-cyclopentoxy-4-methoxyphenyl)-prop-2-enoate (3.1 g, 87%), containing a trace amount of the E-isomer. 1H-NMR (300 MHz): δ 3.74 (s, 3), 3.89 (s, 3), 5.82 (d, 1, J=13).

Provenance & Evidence