A New Synthesis of Vitamin A2 : Conversion of Vitamin A1 to A2
1962; Nature Portfolio; Volume: 193; Issue: 4811 Linguagem: Inglês
10.1038/193165a0
ISSN1476-4687
Autores Tópico(s)Click Chemistry and Applications
ResumoTHE earlier confusion regarding the structure of vitamin A2 was removed by its synthesis1, which conclusively proved it to have the dehydrovitamin A1 formula suggested by Morton, Salah and Stubbs2. In this synthesis an extra double bond was introduced into the β-ionone ring of the methylester of vitamin A1 acid, by bromination with N-bromosuccinimide, followed by dehydrobromination with 4-phenyl morpholine. Reduction with lithium aluminium hydride gave a product which closely agreed with the spectroscopic properties of vitamin A2. Recently, Henbest, Jones and Owen3 carried out an elegant conversion of vitamin A1 to A2 by treating the aldehyde of vitamin A1 (retinene1) with N-bromosuccinimide, to obtain retinene2, which by reduction with lithium aluminium hydride was converted to vitamin A2.
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