31112-52-4Relevant academic research and scientific papers
Synthesis and characterization of norbornanediol isomers and their fluorinated analogues
Grayson, Scott M.,Long, Brian K.,Kusomoto, Shiro,Osborn, Brian P.,Callahan, Ryan P.,Chambers, Charles R.,Willson, C. Grant
, p. 341 - 344 (2007/10/03)
Fluorinated norbornene monomers exhibit the requisite properties for inclusion in 157 nm photoresists, but traditional addition and radical polymerizations with these monomers have failed. Norbornanediols provide an alternate route to these materials via condensation polymerization, and methods have been developed for the efficient synthesis of the exo-2-syn-T- and endo-2-exo-3-dihydroxynorbornanes. Synthesis of the fluorinated analogues is complicated by steric and electronic effects; however, a high-yielding synthesis of endo-2-exo-3-dihydroxynorbornane bearing a 5-endo-[2,2-bis(trifluoromethyl) hydroxyethyl] substituent is reported.
Thiol-catalysed radical-chain redox rearrangement reactions of benzylidene acetals derived from terpenoid diols
Dang, Hai-Shan,Roberts, Brian P.,Tocher, Derek A.
, p. 4073 - 4084 (2007/10/03)
The thiol-catalysed radical-chain redox rearrangement of cyclic benzylidene acetals derived from 1,2- and 1,3-diols of terpene origin has been investigated from both synthetic and mechanistic standpoints. The redox rearrangement was carried out either at ca. 70°C (using ButON=NOBut as initiator) or at ca. 130°C (using ButOOBut as initiator) in the presence of triisopropylsilanethiol or methyl thioglycolate as catalyst; the silanethiol was usually more effective. This general reaction affords the benzoate ester of the monodeoxygenated diol, unless rearrangement of intermediate carbon-centred radicals takes place prior to final trapping by the thiol to give the product, in which case structurally rearranged esters are obtained. For the benzylidene acetals of 1,2-diols prepared by vicinal ds-dihydroxylation of 2-carene, α-pinene or β-pinene, intermediate cyclopropylcarbinyl or cyclobutylcarbinyl radicals are involved and ring opening of these leads ultimately to unsaturated monocyclic benzoates. 1,2-Migration of the benzoate group in the intermediate p-benzoyloxyalkyl radical sometimes also competes with thiol trapping during the redox rearrangement of benzylidene acetals derived from 1,2-diols. Redox rearrangement of the benzylidene acetal from carane-3,4-diol, obtained by cis-dihydroxylation of 3-carene, does not involve intermediate cyclopropylcarbinyl radicals and leads to benzoate ester in which the bicyclic carane skeleton is retained. The inefficient redox rearrangement of the relatively rigid benzylidene acetal from exo,exo-norbornane-2,3-diol is attributed to comparatively slow chain-propagating β-scission of the intermediate 2-phenyl-1,3-dioxolan-2-yl radical, probably caused by the development of adverse angle strain in the transition state for this cleavage. Similar angle strain effects are thought to influence the regioselectivities of redox rearrangement of bicyclic [4.4.0]benzylidene acetals resulting from selected 1,3-diols, themselves prepared by reduction of aldol adducts derived from reactions of aldehydes with the kinetic lithium enolates obtained from menthone and from isomenthone.
ACTION DU N-BROMOSUCCINIMIDE SUR LES DIOXOLANNES EN SERIE BICYCLOHEPTANIQUE. LIMITATION DES TRANSPOSITIONS DE WAGNER-MEERWEIN
Bazbouz, Akram,Christol, Henri,Coste, Jacques,Plenat, Francoise
, p. 2745 - 2755 (2007/10/02)
Vicinal benzoyloxy-trans-bicycloheptanic bromhydrins, otherwise difficult to obtain are formed from N-bromosuccinimide and norbornanes bearing a 2-aryl-1,3 dioxolane skeleton.The greater stability of the intermediate dioxolenium ion reduces the tendency towards both Wagner-Meerwein rearrangement and neighbouring group participation by chlorine, processes usually observed when a less stable intermediate is involved.Nevertheless, methoxycarbonyl neighbouring group participation and Wagner-Meerwein rearrangement occur in methoxycarbonylbicycloheptane and in a bornanic compound respectively.
