The nucleophilic ring opening of gem-dicyanoepoxides by LiBr or Li 2 NiBr 4 , in the presence of hydroxylamine derivatives leads to new α-halo hydroxamic acids. These compounds has been used in the synthesis of αfunctionalized hydroxamic acids, α-hydroxy and α-amino acids in good yields.
Conversion of amino acids and dipeptides into their phosphonic analogs : Aminoalkylphosphonic acids and peptides II
✍ Scribed by George Ösapay; Ildikó Szilagyi; Jenö Seres
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- French
- Weight
- 478 KB
- Volume
- 43
- Category
- Article
- ISSN
- 0040-4020
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✦ Synopsis
Acylamino carboxylic acids were degradated by the Hunsdiecker-reaction; the bromo-derivatives were reacted with NaPO(OQH5)z. Aminophosphonic acids were obtained by acidic hydrolysis, and half-blocked derivatives by the selective removal of masking substituents. Two phosphonopeptides [e.g. Alafosfalin (4i)] were also prepared by this route.
📜 SIMILAR VOLUMES
## Abstract A synthesis of α,β‐dehydroamino acid derivatives **12** is described, which is of possible general applicability and might be useful for the preparation of peptides which have such a moiety in their sequence. In addition, several didehydrodioxopiperazines (**13–17**) have been prepared.
## Abstract __N__‐Protected racemic lipidic amino acids 1a–h were converted directly into ceramide analogues 2a–h by chemoselective reduction of their corresponding mixed anhydrides with sodium tetrahydroborate. Conversion of the compounds 1a, b into the corresponding acyl azides, followed by catal