反应详情

A mixture of 5.0 g of 3-iodo-L-tyrosine (Aldrich) and 2.5 mL of conc. H2SO4 in 85 mL of 1,4-dioxane was added to 30 mL of liquid isobutylene (condensed at −78° C.) in a 300 mL pressure bottle. The vessel was stoppered and the contents stirred at RT. After 3 days the bottle was cooled in an ice water bath, opened and the solution poured into a mixture of 10 g of NaHCO3 in 150 mL of water. The resulting mixture was subjected to rotary evaporation to remove isobutylene and dioxane. A white solid resulted which was collected by filtration and dried in vacuo. Analysis by tlc (SiO2, 95:5 CH2Cl2:MeOH) indicated major and minor components at Rf=0.52 and 0.60 respectively. The crude product was purified by flash chromatography on silica gel (95:5 CH2Cl2:MeOH) to afford 3.4 g (58%) of tert-butyl 3-iodo-L-tyrosinate as a white crystalline solid, m.p. 158-159° C.

1. temperatureAfter 3 days the bottle was cooled in an ice water bath
2. customThe resulting mixture was subjected to rotary evaporation
3. customto remove isobutylene and dioxane
4. customA white solid resulted which
5. filtrationwas collected by filtration
6. customdried in vacuo
7. customThe crude product was purified by flash chromatography on silica gel (95:5 CH2Cl2:MeOH)