32405-37-1Relevant academic research and scientific papers
Palladium(0)-catalyzed cyclization-carbonylation of 2,7-octadienyl acetate and homologues
Terakado, Masahiko,Murai, Kouya,Miyazawa, Masahiro,Yamamoto, Keiji
, p. 5705 - 5718 (2007/10/02)
The palladium(0)-catalyzed carbonylations, in acetic acid as a necessary solvent, of 2,7-octadienyl acetate and homologues via π-allylpalladium species were preceded by their intramolecular olefin insertion to form mixtures of cis/trans-2-vinylcyclopentylacetyl- and cis/trans-cyclohexylacetylpalladium intermediates, which undergo further the intramolecular (5-exo) Heck reaction to give bicyclo-[3.3.0] and [4.3.0] skeletons, respectively, except for one case affording trans-2-vinylcyclopentylacetic acid as a major product.
Structural Effects in Solvolytic Reactions. 50. Steric Retardation in the Solvolysis of Tertiary Endo Bicyclic Derivatives. Evidence That the Exo:Endo Rate/Product Ratios for typical Reactions in Rigid U-Shaped Bicyclics Is a General Steric Phenomenon
Brown, Herbert, C.,Jagt, David L. Vander,Rothberg, Irvin,Hammar, W. James,Kawakami, James H.
, p. 2179 - 2188 (2007/10/02)
The exo:endo rate ratios for the solvolysis in 80percent acetone at 25 deg C of the p-nitrobenzoates of tertiary bicyclic alcohols of widely varying U-shape character, such as 2-methyl- and 3-methyl-cis-bicyclooctanols, 2-methyl-2-norbornanol, and 2-, 8-, and 9-methyl-endo-5,6-trimethylene-2-, -8-, and -9-norbornanols increase with increasing U-shape character of the bicyclic skeleton.This supports the proposal that steric retardation of ionization of the endo isomer is a major factor in governing the exo:endo rate ratios in these tertiary systems.A comparison of the solvolysis data with those of representative nonsolvolytic reactions in these U-shaped systems indicates that the exo/endo relative reactivities reveal a similar pattern for all of the reactions.The exo:endo ratios (product or rate) increase with increasing U-shape character of the bicyclic skeleton.Thus the large exo:endo rate ratio in the solvolysis of tertiary 2-norbornyl derivatives may as well be due to steric rather than to the long proposed electronic factor.
CYCLIC α,β-EPOXYSILANES ACID-CATALYSED REACTIONS OF 1-TRIMETHYLSILYLCYCLOOCTENE OXIDE
Nagendrappa, Gopalpur
, p. 2429 - 2434 (2007/10/02)
The acid-catalysed reactions of medium ring α,β-epoxysilane 1 are described.The epoxide 1 gives exclusively the bicyclic alcohol 2 with boron trifluoride etherate.With aqueous sulphuric acid the products are due to both transannular ring closure, 2, and transannular hydride migration, 3 and 4. trans-Cyclooctene derivatives 3 and 4 are formed by the trans-elimination of trimethylsilanol from the likely intermediate β-hydroxysilanes 10 and 11.The results with methanolic sulphuric acid are similar.It is also noticed that the hydride migration is facilitated by the nucleophilic strength of the medium.
