Reacción #65049

Ecuación de reacción

ethyl ether

methoxymethyltriphenyl phosphonium chloride

potassium t-butoxide

3-(4-carboxymethylphenyl)-propanal

→

1-methoxy-4-(4-carboxymethyl phenyl)-1-butene

Rendimiento 78.1%

Disolventes

toluene

tetrahydrofuran

toluene

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONwere added
2. 2
   FiltraciónThe resulting precipitate was filtered with diatomaceous earth
3. 3
   Otrocollected
4. 4
   Lavadowashed with 20 ml of water, 20 ml of saturated sodium chloride
5. 5
   Secadodried with a 9:1 sodium sulfate

Procedimiento

To 3.77 g (11 mmol) of methoxymethyltriphenyl phosphonium chloride in 10 ml of toluene at 0° C. under nitrogen was added 11 ml (11 mmol) of 1M potassium t-butoxide in tetrahydrofuran over 20 minutes. The resulting solution was stirred for 10 minutes, then 1.92 g (10 mmol) of 3-(4-carboxymethylphenyl)-propanal in 10 ml of toluene was added over 15 minutes. After stirring the mixture for 20 minutes 40 ml of ethyl ether were added. The resulting precipitate was filtered with diatomaceous earth, collected, washed with 20 ml of water, 20 ml of saturated sodium chloride and dried with a 9:1 sodium sulfate:saturated sodium chloride mixture. Vacuum concentration of the filtered solution and trituration of the residue with hexane gave 1.72 g of 1-methoxy-4-(4-carboxymethyl phenyl)-1-butene. Chromatography of the above product (silica gel, 8:2 hexane:ethyl acetate) gave 1.0 g of a mixture of geometric isomers (Z/E-6:4) of the above product in a combined yield of 45 percent. b.p. 140° C. @0.07 torr. 1H NMR (CDCl3) δ2.23 (dq, J=1.0, 8.1 Hz), 2.40 (dq, J=1.3, 8.0 Hz) total 2H, 2.70 (t, J=8.1 Hz), 2.71 (t, J=8.0 Hz), total 2H, 3.48 (s), 3.55 (s), total 3H, 3.89 (s), 3.90 (s), total 3H, 4.32 (q, J=6.2 Hz), 4.71 (dr, J=7.3, 12.6 Hz), total 1H, 5.87 (dr, J=1.3, 6.2 Hz), 6.28 (dt, J=1.0, 12.6 Hz) , total 1H, 7.23 (d, J=8.2 Hz), 7.27 (d, J=8.2 Hz), total 1H, 7.94 (d, J=8.2 Hz), 7.95 (d, J=8.2 Hz), total 2H; 13C NMR (CDCl3) δ8 25.2, 29.3, 36.0, 37.4, 51.9, 56.0, 59.5, 101.8, 101.9, 105.5, 127.9, 28.0, 128.5, 128.6, 129.6, 129.7, 146.9, 147.5, 147.9, 48.0, 167.1, 167.2; IR (CHCl3) 3025, 2954, 1716, 1656, 1610, 1437, 1284, 1112 cm-1 ; MS(FD) m/z 220 (M+).

Fuente