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1、长叶烯Strategicbondandretro-syntheticanalysis1:CoreySynthesisJACS1961,83,1251;JACS1964,86,478.CoreySynthesisPinacolRearrangementLiClO4usedforfreeLi+iontoacceleratesolvolyticlossofTsO-group.Migrationofunsaturatedalkylgroupobservedpreferentially.Transantiperiplanararrangeme
2、ntCoreySynthesisIntramolecularMichaelAdditionOnlycisproductundergoesMichael.Sideproductsincludetheretro-MichaelproductAandtheOH-additionandretro-aldolproductB.2.McMurrySynthesisJACS1972,94,7132.McMurrySynthesisHydrogenationKnownconditiontogivecisstereochemistryH2comesi
3、nfromlesshinderedfaceHeteroatomscanalsodirecteH2totheirfaceMcMurrySynthesisEpoxidationEpoxidationfromtheleasthinderedfaceNocompetitiveBaeyer-VilligeratketoneTrisubstitutedolefinmorereactivethanketoneMcMurrySynthesisIntramolecularEpoxideAdditionVeryslowepoxideopeningdue
4、tostericencumbranceofMegroupBenefitsfromirreversiblenatureofepoxideopeningMcMurrySynthesisRingExpansionRingcontrolgeometryofringopening,thusonlyonebrominedepartsNucleophile(OH2)enterstranstoleaveBrNotrapatotherendofallylcation---possibleassistanceofC=OMcMurrySynthesisC
5、uprateAddition---IntramolecularAldolRxnCuprateaddsinMichaelfashiontogenerateenolateEnolatethenattackscarbonylinintramolecularfashionMcMurrySynthesisFragmentationReductionoccursfromleasthinderedfaceTosylationselectivefor2o>3o3.BriegerSynthesisJACS1963,85,37834.JohnsonSy
6、nthesisJACS1975,97,4777.JohnsonSynthesisCation-OlefinCyclization2oallylalcoholforinitiationsite5.OppolzerSynthesisJACS1978,100,2583.6.SchultzSynthesisJOC1985,50,916.SchultzSynthesisRetroCheletropicCycloadditionandSubsequent1,3-DipolarCycloadditionSchultzSynthesisVinylc
7、yclopropaneRearrangement1,3-sigmatropicrearrangementIsthis[4e+2e]cycloadditionpossible?ConsiderWoodward-Hoffmannrules.7.FallisSynthesisJACS1990,112,4609.FallisSynthesisIntramolecularDiels-AlderRxnConstraintsofthe6-memberedringprecludesreactionfromtheothercyclopentadien
8、eisomersandlactonestereochemistrydictatesp–facialselectivity.8.KuoSynthesisCanJ.Chem.1988,66,1794.KuoSynthesisWagner-
