✦ LIBER ✦
262. Magnetische Nicht-Áquivalenz von Protonen als Folge konformativer Chiralität Kinetik einer Racemisierung
✍ Scribed by F. Conti; C. H. Eugster; W. Von Philipsborn
- Publisher
- John Wiley and Sons
- Year
- 1966
- Tongue
- German
- Weight
- 437 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0018-019X
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✦ Synopsis
A convenient synthesis for the preparation of 3,5,4', 5'-tetraniethoxydiplienic acid is described, wherein veratralacetone is condensed with diethyl malonate and the resulting product converted to the ethyl ester of 4,6-dibromo-3,5-dihydroxy-3', 4'dimethoxybiphenyl-2-carboxylic acid. After methylation, the corresponding dibromotetramethoxy ester is chloromethylated at the 2' position. This latter compound is successively hydrolyzed, oxidized, and debrominated to 3,5,4', 5'-tetramethoxydiphenic acid, identical in all respects with that obtained from protostephaqine by degradation.