反应详情

A solution of (3S,4S)-4-(1-hydroxymethylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone (106 mg) and dihydropyran (25 mg) in dry dichloromethane (1 ml) was treated with p-toluenesulfonic acid (1 mg) at room temperature for 50 minutes. The reaction mixture was diluted with ethyl acetate, washed with brine and dried over anhydrous sodium sulfate. Filtration and concentration of the filtrate in vacuo gave an oily residue, which was purified by thin-layer chromatography (SiO2) to yield (3S,4S)-4-(1-tetrahydropyranyloxymethylethenyl)-3-(1-(R)-benzyloxycarbonyloxyethyl)-1-di(p-anisyl)methyl-2-azetidinone.

1. washwashed with brine
2. dry with materialdried over anhydrous sodium sulfate
3. filtrationFiltration and concentration of the filtrate in vacuo
4. customgave an oily residue, which
5. customwas purified by thin-layer chromatography (SiO2)