1-Methyl(or phenyl)-5-(penta-O-acetyl-d-galacto-pentitol-1-yl)pyrazoles from the reactions of 3,4,5,6,7-penta-O-acetyl-1,2-dideoxy-1-nitro-d-galacto-hept-1-enitol with aldehyde methyl(or phenyl)hydrazones
✍ Scribed by Manuel Gómez-Guillén; José María Lassaletta Simon
- Publisher
- Elsevier Science
- Year
- 1991
- Tongue
- English
- Weight
- 887 KB
- Volume
- 210
- Category
- Article
- ISSN
- 0008-6215
No coin nor oath required. For personal study only.
✦ Synopsis
The title hept-I -enitol( 2) reacted with aldehyde methyl(or phenyl)hydrazones in refluxing methanol or butyl acetate to give I-methyl(or phenyl)-5-(penta-O-acetyl-~-~~u~u~f~~-pentitol-l-yl)pyrazoles in good (for I-methylpyrazoles) or moderate yields (for I-phenylpyrazolcs). The 0-deacetylated products were obtained in high yields. A Michael-type adduct was obtained for the reactions of2 with p-tolualdehyde and p-nitrobenzaldehyde methylhydrazones. and its role as an intermediate was proved by conversion into the pyrazole derivative under the conditions of the above reactions. Only for the reaction with formaldehyde phenylhydrazone was the observed regioselectivity abnormal. The structures proposed were confirmed by spectral data.