Reaction #1098

Reaction equation

4-(O-benzylhydroxylamino)-3-methoxy-2-methylpyridine

sodium hydride

3,3-dimethyl-9-tosyloxy-1,5-dioxaspiro[5.5]undecane

hydrogen

→

4-[O-Benzyl-N-(3,3-dimethyl-1,5-dioxaspiro[5.5]undec-9-yl)hydroxylamino]-3-methoxy-2-methylpyridine

Solvents

THF

DMSO

Conditions

Workup

1. 1
   workup.DISTILLATIONThe THF is then distilled off in vacuo
2. 2
   workup.ADDITIONthe mixture is poured into water
3. 3
   ExtractionAfter extracting with methylene chloride
4. 4
   Otherthe product is purified by chromatography on silica gel (ethyl acetate)

Procedure

7.3 g of 4-(O-benzylhydroxylamino)-3-methoxy-2-methylpyridine in 30 ml of absolute DMSO are deprotonated under N2 using 0.9 g of sodium hydride (80% strength). After evolution of hydrogen has ended, 11.7 g of 3,3-dimethyl-9-tosyloxy-1,5-dioxaspiro[5.5]undecane are added in 50 ml of absolute THF. The mixture is stirred at room temperature for 1 hour and at 50° C. for 4 hours. The THF is then distilled off in vacuo and the mixture is poured into water. After extracting with methylene chloride, the product is purified by chromatography on silica gel (ethyl acetate). 6.5 g=51%

Source