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A Novel Method for a Stereoselective Synthesis of Trisubstituted Olefin Using Tricarbonyliron Complex: A Highly Stereoselective Synthesis of ( all-E )- and (9 Z )-Retinoic Acids

1997; American Chemical Society; Volume: 62; Issue: 13 Linguagem: Inglês

10.1021/jo961041+

1520-6904

Akimori Wada, Saeko Hiraishi, Norio Takamura, Tadamasa Date, K. AOE, Masayoshi Ito,

Porphyrin and Phthalocyanine Chemistry

In order to establish the stereoselective synthesis of retinoic acids, which are ligand molecules of the retinoic acid receptors (RARs, all-E-isomer) and the retinoid X receptors (RXRs, 9Z-isomer), the reaction of beta-ionone-tricarbonyliron complex 7 with carbanions was investigated. Treatment of 7 with the lithium salt of acetonitrile afforded (7E,9E)-beta-ionylideneacetonitrile-tricarbonyliron complex 8 exclusively, via addition, dehydration, and migration of tricarbonyliron complex. On the contrary, the reaction of 7 with the lithium enolate of ethyl acetate and subsequent dehydration by thionyl chloride afforded the ethyl (7E,9Z)-beta-ionylideneacetate-tricarbonyliron complex 16b predominantly. These compounds (8 and 16b) were converted to the corresponding beta-ionylideneacetaldehyde-tricarbonyliron complexes (10 and 22) in excellent yields, respectively. The Emmons-Horner reaction of these compounds with C5-phosphonate followed by the sequence of decomplexation and alkaline hydrolysis gave the corresponding retinoic acids (26 and 29).