<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Friestad, Gregory K.</style></author><author><style face="normal" font="default" size="100%">Ji, An</style></author><author><style face="normal" font="default" size="100%">Baltrusaitis, Jonas</style></author><author><style face="normal" font="default" size="100%">Korapala, Chandra Sekhar</style></author><author><style face="normal" font="default" size="100%">Qin, Jun.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Scope of stereoselective Mn-mediated radical addition to chiral hydrazones and application in a formal synthesis of quinine.</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Organic Chemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">alkyl iodide acylhydrazone radical additive cyclization manganese</style></keyword><keyword><style  face="normal" font="default" size="100%">azabicyclooctane ring system stereoselective prepn</style></keyword><keyword><style  face="normal" font="default" size="100%">manganese radical addn cyclization mediator</style></keyword><keyword><style  face="normal" font="default" size="100%">quincorine prepn intermediate quinine</style></keyword><keyword><style  face="normal" font="default" size="100%">quinine formal synthesis</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2012</style></year><pub-dates><date><style  face="normal" font="default" size="100%">2012///</style></date></pub-dates></dates><publisher><style face="normal" font="default" size="100%">American Chemical Society</style></publisher><volume><style face="normal" font="default" size="100%">77</style></volume><pages><style face="normal" font="default" size="100%">3159 - 3180</style></pages><isbn><style face="normal" font="default" size="100%">0022-3263</style></isbn><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Stereocontrolled Mn-mediated addn. of alkyl iodides to chiral N-acylhydrazones enables strategic C-C bond constructions at the stereogenic centers of chiral amines.  Applying this strategy to quinine suggested complementary synthetic approaches to construct C-C bonds attached at the nitrogen-bearing stereogenic center using multifunctional alkyl iodides, e.g, I, as radical precursors, or using multifunctional chiral N-acylhydrazones, e.g., II, as radical acceptors.  These were included among Mn-mediated radical addns. of various alkyl iodides to a range of chiral N-acylhydrazone radical acceptors, leading to the discovery that pyridine and alkene functionalities are incompatible.  In a revised strategy, these functionalities are avoided during the Mn-mediated radical addn. of I to chiral N-acylhydrazone II, which generated a key C-C bond with complete stereochem. control at the chiral amine carbon of quinine.  Subsequent elaboration included two sequential cyclizations to complete the azabicyclo[2.2.2]octane ring system.  Group selectivity between two 2-iodoethyl groups during the second cyclization favored an undesired azabicyclo[3.2.1]octane ring system, an outcome that was found to be consistent with transition state calcns. at the B3LYP/6-31G(d) level.  Group differentiation at an earlier stage enabled an alternative regioconvergent pathway; this furnished the desired azabicyclo[2.2.2]octane ring system and afforded quincorine, completing a formal synthesis of quinine. [on SciFinder(R)]</style></abstract><issue><style face="normal" font="default" size="100%">7</style></issue><notes><style face="normal" font="default" size="100%">CAPLUS AN 2012:213999(Journal; Online Computer File)</style></notes></record></records></xml>