반응 #484470

반응 방정식

sodium hydrogen carbonate

3-bromo-2-hydroxyiminopropionic acid ethyl ester

sodium carbonate

(1R)-1,5-anhydro-1-C-(2-indolyl)-2,3,4,6-tetra-O-benzyl-D-mannitol

compound ( VII )

(1R)-1,5-anhydro-1-C-(2-indolyl)-2,3,4,6-tetra-O-benzyl-D-mannitol

→

2-hydroxyimino-3-[2-(2,3,4,6-tetra-O-benzyl-α-D-mannopyranosyl)indole-3-yl]propionic acid ethyl ester

수율 37.3%

용매

dichloromethane

반응 조건

후처리

1. 1
   추출was then subjected to extraction with dichloromethane
2. 2
   세척The extracted solution was washed with water
3. 3
   건조dried on anhydrous sodium sulfate
4. 4
   기타After removal of the solvent
5. 5
   workup.DISTILLATIONby distillation

실험 절차

First, 2.08 g (3.24 mmol) of (1R)-1,5-anhydro-1-C-(2-indolyl)-2,3,4,6-tetra-O-benzyl-D-mannitol [compound (VII) wherein R1 to R4 are benzyl] was dissolved in dichloromethane (160 ml). Then, 1.36 g (6.49 mmol) of 3-bromo-2-hydroxyiminopropionic acid ethyl ester [compound (VIII) wherein R6 is ethyl] and 1.03 g (9.74 mmol) of sodium carbonate powder were added to the mixture and stirred at room temperature for about 1.5 hours. Then, a saturated aqueous solution of sodium hydrogen carbonate was added to the reaction mixture which was then subjected to extraction with dichloromethane. The extracted solution was washed with water and then dried on anhydrous sodium sulfate. After removal of the solvent by distillation, the residue was fractionated by column chromatography on silica gel [silica gel: Merck Kieselgel 60 (230-400 mesh ASTM); elution solvent: n-hexane and ethyl acetate (3:1)] to give 1.04 g (recovery 50%) of the starting material and 0.93 g (yield 37%) of 2-hydroxyimino-3-[2-(2,3,4,6-tetra-O-benzyl-α-D-mannopyranosyl)indole-3-yl]propionic acid ethyl ester [compound (IX) wherein R1 to R4 are benzyl and R6 is ethyl].

출처