反应详情

To 5-(2'-hydroxy-3', 4', 6'-trimethylbenzoyl)pentanoic acid (formula II-1 wherein R=H3C, X=H, Y=OH, n=4 , in the free form) (0.262 part) were added water (16 volume parts), toluene (20 volume parts), concentrated hydrochloric acid (4 volume parts) and zinc amalgam prepared from 2 parts of zinc. The mixture was refluxed for 16 hours, during which time concentrated hydrochloric acid (6 volume parts) was added in three portions. After cooling, the reaction mixture was diluted with water and extracted with diethyl ether. The extract was washed with water and dried. The solvents were distilled off under reduced pressure to obtain 6-(2'-hydroxy-3', 4', 6'-trimethylphenyl)hexanoic acid (formula II-2 wherein R=H3C, X=H, Y=OH, n=4, in the free form) (0.251 part) as colorless needles melting at 96°-108° C.

1. additionwas added in three portions
2. temperatureAfter cooling
3. extractionextracted with diethyl ether
4. washThe extract was washed with water
5. customdried
6. distillationThe solvents were distilled off under reduced pressure