Toluene → 2-Ethyl-4-[6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-but-2-enal

Participants

Reaction Steps

A solution of [6-methoxy-7-methyl-3-oxo-4-(2-trimethylsilanyl-ethoxy)-1,3-dihydro-isobenzofuran-5-yl]-acetaldehyde (1.5 g, 4.46 mmol) in toluene (14 mL) was heated at 100° C. with 2-(triphenyl-phosphanylidene)-butyraldehyde (1.68 g, 5.35 mmol) overnight. A second portion of 2-(triphenyl-phosphanylidene)-butyraldehyde (495 mg, 1.49 mmol) was added and the reaction mixture was heated for an additional day. After concentration, the residue was purified by silica gel chromatography to provide 1.3 g (83%) of the desired product as oil. 1H NMR (300 MHz, CDCl3) δ 0.01 (s, 9H), 1.03 (t, 3H), 1.10-1.21 (m, 2H), 2.15 (s, 3H), 2.15-2.44 (m, 2H), 3.67-3.76 (m, 2H), 3.74 (s, 3H), 4.31-4.36 (m, 2H), 5.10 (s, 2H), 6.34-6.38 (m, 1H), 9.28 (s, 1H) ppm.

Provenance & Evidence