| Autor: |
Doyle, Terrence William, Luh, Bing-Yu, Martel, Alain |
| Zdroj: |
Canadian Journal of Chemistry; July 1977, Vol. 55 Issue: 14 p2700-2707, 8p |
| Abstrakt: |
The synthesis of 1-α-methyl and 1-β-methyl isomers of 7-(3-phenoxyacetamido-1,3-dimethyl-Δ3-O-2-isocephem-4-carboxylic acids (14aand 14b) is described. Treatment of amine 2with methacrolein followed by cycloaddition gave 4which was ozonolyzed to yield the methyl ketones 6. Upon reduction of 6there was obtained a mixture of isomeric alcohols 8which were resolved by column chromatography, converted to their mesylates 9, and hydrolyzed to yield 10aand 10b. Conversion of each isomer to the corresponding O-2-isocephems 11aand 11bfollowed by azide reduction, coupling of the amines to phenoxyacetic acid, and removal of the ester blocking groups gave 14aand 14b. An attempt to prepare the gem-dimethyl compound failed. The structural assignments to 14aand 14bare discussed. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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