Reacción #577222

Ecuación de reacción

NaOH

17

2-[3-Oxo-6-(2-propenyloxy)-3H-xanthen-9-yl]-benzoic acid 2-propenyl ester

→

18

Rendimiento 65.0%

3′-Hydroxy-6′-(2-propenyloxy)-spiro[isobenzofuran-1(3H), 9′-[9H]xanthen]-3-one

Rendimiento 65.0%

Disolventes

methanol

Condiciones de reacción

Tratamiento posterior

1. 1
   ConcentraciónThe mixture was concentrated
2. 2
   workup.ADDITIONdiluted with ethyl acetate
3. 3
   Lavadowashed with 10% NaHCO3, brine
4. 4
   Secadodried with anhydrous Na2SO4
5. 5
   Otroevaporated
6. 6
   OtroThe residue was purified by column chromatography (ethyl acetate/hexane=1:1)

Procedimiento

NaOH (20 mL, 1.0 M, 20.0 mmol) was added to a solution of 17 (0.40 g, 0.97 mmol) in methanol (60 mL). The resulting mixture was stirred for 2 h at room temperature. The mixture was concentrated, diluted with ethyl acetate, washed with 10% NaHCO3, brine, dried with anhydrous Na2SO4, and evaporated. The residue was purified by column chromatography (ethyl acetate/hexane=1:1) to give 18 as a yellow solid (0.23 g, 65%). TLC (ethyl acetate/hexane, 3:1): Rf=0.6. mp 204° C. 1H NMR (CDCl3/CD3OD, 500 MHz) δ 4.58 (d, J=5.0 Hz, 2H, CH2), 5.32 (d, J=10.5 Hz, 1H, CH), 5.43 (d, J=17.5 Hz, 1H, CH), 6.04 (m, 1H, CH), 6.62 (m, 4H), 6.74 (s, 1H), 6.80 (s, 1H), 7.20 (d, J=7.5 Hz, 1H), 7.65 (t, J=7.5 Hz, 1H), 7.71 (t, J=7.5 Hz, 1H), 8.01 (d, J=7.5 Hz, 1H). 13C NMR (CDCl3/CD3OD, 125 MHz) δ 69.00, 101.71, 102.73, 109.90, 111.21, 111.94, 112.42, 117.89, 124.04, 124.80, 126.69, 128.88, 128.95, 129.72, 132.51, 135.16, 152.56, 160.28, 170.26. ESIMS calcd for C23H17O5 [M+H]+ 373.1. Found 373.2.

Fuente