3-Cyclobutene-1,2-dione, 3,4-dimethoxy- → 3-Methoxy-4-tributylstannanylcyclobut-3-ene-1,2-dione

Participants

Reaction Steps

To a solution of 3,4-dimethoxy-cyclobut-3-ene-1,2-dione (1.5 g, 10.6 mmol) and trimethyl(tributylstannyl)silane (3.7 mL, 10.6 mmol) in anhydrous THF (75 mL) at −30° C. was added drop-wise a solution of tetrabutylammonium cyanide (57 mg, 0.2 mmol) in THF (3 mL). The clear solution quickly turned yellow and was left to warm to rt overnight. The reaction was concentrated in vacuo revealing a black oil which was dissolved in ether and filtered through a plug of silica (100% ether). The crude material was further purified by silica gel chromatography (100% hexanes to 3% Et2O in hexanes) to yield 3-methoxy-4-tributylstannanylcyclobut-3-ene-1,2-dione as a light yellow oil. 1H NMR (DMSO-d6, 400 MHz): δ0.90 (t, J=7.2 Hz, 9H), 1.09-1.23 (m, 6H), 1.23-1.38 (m, 6H), 1.43-1.63 (m, 6H), 4.38 (s, 3H).

Provenance & Evidence