[N:1]([CH2:4][C:5]([C:7]1[CH:8]=[CH:9][C:10]2[O:14][C:13]([CH3:16])([CH3:15])[S:12][C:11]=2[CH:17]=1)=[O:6])=[N+]=[N-].[CH:18]([O-])=[O:19].[Na+].C(OC(=O)C)=O>C(O)=O>[CH:18]([NH:1][CH2:4][C:5]([C:7]1[CH:8]=[CH:9][C:10]2[O:14][C:13]([CH3:16])([CH3:15])[S:12][C:11]=2[CH:17]=1)=[O:6])=[O:19]10 g of 5-azidoacetyl-2,2-dimethyl-1,3-benzoxathiole (VIII) was added portionwise to a cooled solution of 20 g stannous chloride and 7 g sodium formate in the mixture of 16 ml of acetic-formic anhydride and 9 ml of formic acid. After 14 hours at room temperature the mixture was quenched with ice and dilute hydrochloric acid and extracted with ethyl acetate. The extract was dried over MgSO4, evaporated, and the residue purified by chromatography through a column of silica gel eluted with ethyl acetate-hexane (1:1) to yield 6 g of 5-formamidoacetyl-2,2-dimethyl-1,3-benzoxathiole (IX) as a yellow oil.
불러오는 중…