Reacción #76274

Ecuación de reacción

Methyl lithium

8-Hydroxy-2-(6-hydroxy-5,5-dimethyl-hexyl)-7,7-dimethyl-octanoic acid

7-(1-hydroxy-1-methylethyl)-2,2,12,12-tetramethyltridecan-1,13-diol

hydrochloric acid

→

9-hydroxy-3-(6-hydroxy-5,5-dimethyl-hexyl)-8,8-dimethyl-nonan-2-one

Rendimiento 41.0%

Disolventes

THF

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturacooled in an ice-water bath
2. 2
   OtroThe organic layer was separated
3. 3
   Extracciónthe aqueous layer was extracted with diethyl ether (2×50 mL)
4. 4
   SecadoThe combined organic layers were dried over sodium sulfate
5. 5
   Concentraciónconcentrated in vacuo
6. 6
   Otroto give the crude product (1.0 g)
7. 7
   OtroThe crude product was purified by column chromatography (hexanes

Procedimiento

8-Hydroxy-2-(6-hydroxy-5,5-dimethyl-hexyl)-7,7-dimethyl-octanoic acid (1.0g, 3.16 mmol) was dissolved in THF (40 mL) and cooled in an ice-water bath. Methyl lithium (27 mL) was then added at once. The reaction was continued for 2 h at 0° C. The reaction mixture was poured into dilute hydrochloric acid (5 mL concentrated hydrochloric acid in 60 mL water). The organic layer was separated and the aqueous layer was extracted with diethyl ether (2×50 mL). The combined organic layers were dried over sodium sulfate and concentrated in vacuo to give the crude product (1.0 g). The crude product was purified by column chromatography (hexanes : ethyl acetate=4:1, then 1:1) to give 9-hydroxy-3-(6-hydroxy-5,5-dimethyl-hexyl)-8,8-dimethyl-nonan-2-one (0.41 g, yield 41%) and 7-(1-hydroxy-1-methylethyl)-2,2,12,12-tetramethyltridecan-1,13-diol (0.4 g, 38%, not shown) as a by-product. 1H NMR (300 MHz, CDCl3/TMS): δ (ppm) 3.46 (s, 4H), 2.65-2.50 (m, 1H), 2.28 (s, 3H), 2.60 (br., 2H), 1.82-1.50 (m, 4H), 1.50-1.25 (m, 12H), 1.02 (s, 12H). 13C NMR (75 MHz, CDCl3/TMS): δ (ppm) 213.4, 71.7, 53.2, 38.3, 31.6, 28.7, 28.3, 23.8. HRMS (LSIMS, nba): Calcd. for C19H39O3 (MH+): 315.2899, found: 315.2866.

Fuente