83587-93-3Relevant academic research and scientific papers
Photoinduced Molecular Transformations. Part 155. General Synthesis of Macrocyclic Ketones based on a Ring Expansion involving a Selective β-Scission of Alkoxyl Radicals, its Applications to a New Synthesis of (+/-)-Isocaryophyllene and (+/-)-Caryophyllene, and a Conformational Analy...
Suginome, Hiroshi,Kondoh, Takahiko,Gogonea, Camelia,Singh, Vishwakarma,Goto, Hitoshi,Osawa, Eiji
, p. 69 - 82 (2007/10/02)
The method used for a general synthesis of macrocyclic ketones based on a ring expansion involving a selective β-scission of alkoxyl radicals devised by Suginome and Yamada was extended and modified.Thus, cycloalkanones were transformed into the corresponding α-(ω-iodoalkyl)-cycloalkanones by alkylation of the corresponding lithium enolates with either 1,3-diiodopropane or 1,4-diiodobutane.Treatment of these α-iodoalkyl cyclic ketones with samarium iodide gave bicyclic tertiary alcohols.The generation of the alkoxyl radicals from the bicyclic alcohols by irradiation of the corresponding hypoiodites generated with mercury(II) oxide - iodine - pyridine in benzene resulted in a selective β-scission of their ring-junction bond to give high yields of macrocyclic ketones carrying an iodine which can be removed with tributyltin hydride.The method was then applied to new syntheses of (+/-)-isocaryophyllene and (+/-)-caryophyllene.Thus, ω-iodopropylation of ethyl 7,7-dimethyl-2-oxobicyclooctane-3-carboxylate, followed by cyclization of the resulting α-(ω-iodoalkyl)cycloalkanone with samarium diiodide, gave cis-transoid-cis-ethyl 1-hydroxy-4,4-dimethyltricyclo2,5>undecane-8-carboxylate (69percent).The ethoxycarbonyl group of this tricyclic alcohol was transformed into a methyl group by the standard method.Irradiation of a solution of the hypoiodite, prepared by the method mentioned above, with Pyrex-filtered light gave the corresponding cis-bicycloundecenone (15percent), its exomethylene isomer (2,5>undecan-1-ol mentioned above were correlated with the three products.
β-Scission of 8-Hydrindanoxyl and Related Free Radicals
O'Dell, Dale E.,Loper, John T.,Macdonald, Timothy L.
, p. 5225 - 5229 (2007/10/02)
The β-scission of alkoxyl free radicals prepared from thermolysis (77 deg C) of the in situ generated hypoiodite derived from structurally related hydrindan-8-ol and hydrinden-8-ol systems was examined.The course of alkoxyl radical β-scission was sensitive to changes in alkyl substitution at the ring junction site and olefin introduction in the hydrindan skeleton.Thus, the cleavage pattern must reflect the interplay of multiple thermodynamic and kinetic factors.
