Methyl acetoacetate → Methyl (E)-7-(2,4-dichloro-6-phenylmethoxyphenyl)-5-hydroxy-3-oxo-6-heptenoate

Participants

Reaction Conditions

Reaction Steps

Methyl acetoacetate (9.56 g, 82.3 mmole) was added dropwise to a stirred suspension of sodium hydride (50% oil suspension) (3.95 g, 82.3 mmole) in anhydrous tetrahydrofuran at 0° C. under a nitrogen atmosphere. The resulting solution was stirred 15 minutes at 0° C. and then treated with a 1.6 M solution (51.5 ml, 82.3 mmole) of n-butyllithium in hexane over 5 minutes. The resulting yellow solution was stirred 15 minutes at 0° C. and then treated with a solution of (E)-2,4-dichloro-6-phenylmethoxycinnamaldehyde (25.3 g, 82.3 mmole) in anhydrous tetrahydrofuran (150 ml). The resulting orange solution was stirred 15 minutes at 0° C. and then quenched by dropwise addition of 12 N hydrochloric acid (ca. 20 ml). The reaction mixture was diluted with water (100 ml) and extracted with ether (3×300 ml). The organic extracts were combined, washed with brine (3×100 ml), dried over magnesium sulfate and filtered. The filtrate was evaporated in vacuo leaving the title compound as a yellow oil (34.8 g, 100%): pmr (CDCl3) δ2.75 (2H, d), 3.45 (2H, s), 3.72 (3H, s), 4.71 (H, m), 5.50 (2H, s), 7.37 (5H, s).

Provenance & Evidence