Trimethyl Phosphonoacetate

• Trimethyl Phosphonoacetate [P1265]
• Sodium Hydride (= NaH) (60%, dispersion in Paraffin Liquid) [S0481]
• p-Anisaldehyde [A0480]
• THF

Sodium hydride (60%, 243 mg, 6.1 mmol) was added to dehydrated THF (20 mL) and stirred in an ice bath. Then, trimethyl phosphonoacetate (1.02 g, 5.6 mmol) was added dropwise to the suspension and the mixture was stirred for 3 h at the same temperature. p-Anisaldehyde (635 mg, 4.66 mmol) was added and the mixture was stirred for 4 h at room temperature. The mixture was diluted with diethyl ether (20 mL) and washed with brine (20 mL). The organic layer was dried over anhydrous sodium sulfate and concentrated under reduced pressure. The crude product was purified by silica gel column chromatography (hexane:ethyl acetate = 4:1) to afford ethyl 4-methoxycinnamate (780 mg, 87% yield) as a white solid.

The reaction solution was monitored by UPLC.
THF was dehydrated with molecular sieves 4A before use.
In this reaction, only E-olefin was afforded.

Ethyl 4-Methoxycinnamate

¹H NMR (400 MHz, CDCl₃); δ 7.67 (d, J = 16.0 Hz, 1H), 7.48 (d, J = 8.8 Hz, 2H), 6.90 (d, J = 8.6 Hz, 2H), 6.31 (d, J = 16.0 Hz, 1H), 3.84 (s, 3H), 3.79 (s, 3H).

• Catalytic Asymmetric Cyclopropanation of Allylic Alcohols with Titanium-TADDOLate:  Scope of the Cyclopropanation Reaction
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• Pd-Catalyzed Sequential C–C Bond Formation and Cleavage: Evidence for an Unexpected Generation of Arylpalladium(II) Species
• S. W. Youn, B. S. Kim, A. R. Jagdale, J. Am. Chem. Soc. 2012, 134, 11308.