Trienediolates of hexadienoic acids in synthesis. Addition to unsaturated ketones. A convergent approach to the synthesis of retinoic acids
作者:Maria J. Aurell、Luisa Ceita、Ramon Mestres、Margarita Parra、Amparo Tortajada
DOI:10.1016/0040-4020(95)00114-n
日期:1995.3
The regioselectivity of the addition of the lithium trienediolates generated from hexa-2,4dienoic acids 1 and 2 or the dihydropyran-2ones 4 and 5 to unsaturated ketones 6 is studied. Equilibration conditions favour reaction of the trienediolates through their ω carbon, and the ketones according to 1,2- and 1,4-additions. β-Ionone 6a and the aryl-butenone 6b lead to the 1,2-ω-adducts 8, which undergo
Ligand‐Promoted Rh
<sup>I</sup>
‐Catalyzed C2‐Selective C−H Alkenylation and Polyenylation of Imidazoles with Alkenyl Carboxylic Acids
作者:Haoqiang Zhao、Zhenli Luo、Ji Yang、Bohan Li、Jiahong Han、Lijin Xu、Wenzhen Lai、Patrick J. Walsh
DOI:10.1002/chem.202200441
日期:2022.6.27
readily available alkenyl carboxylicacids is reported. The reaction proceeds in a highly regio- and stereoselective manner, providing efficient access to C2-alkenylated imidazoles that are generally inaccessible by known C-H alkenylation methods. This transformation accommodates a wide range of alkenyl carboxylicacids, including challenging conjugated polyene carboxylicacids, and diversely decorated
Benzocyclization of 2,4-Hexadienoic Acids. Synthesis of (<i>R</i>)-(-)-Curcuphenol Acetate
作者:D. Murali、G. S. Krishna Rao
DOI:10.1055/s-1987-27905
日期:——
A simple and general benzocyclization sequence, useful in the conversion of α-methylene ketones/aldehydes 1a-f to phenolic acetates 6a-g via the dienoic acids 5a-g is presented. The technique has provided a new route to the terpenoids, thymol acetate (6f) and (R)-(-)-curcuphenol acetate (6g).