HCNucCH2R'RHCLGR'H2CRCH2R'CLGHRCCHRHCNucCH2R'RHCNucR'H2CRHCCHRHR'LGCCRHR'HCh. 7 ----- SN1, SN2, E1, E2 Nolta 2009Nuc+ LGSN2 or Bimolecular SubstitutionElectrophilic sp3 carbon (due to LG taking electrons)One-sided attack leads to inversion at C-stereocenters "invert" so watch for stereoselectionOne stepslow stepCCNuc:RHR'H+Racemization at αcenterC+ intermediate-racemization at αcarbon if chiral at start.BaseE2 or "Anti" elimination - FIND ALL POSSIBLE βCs with Hs:The LG and the βH removed from the adjacent C must be in the same planein order for the p orbitals to align, hence the "anti" conformation leads to the fastest E2. This alignment determines the configuration of the double bond that forms; ifmore than one βH is available on a βC, both double bond stereochemistries are possible (anti alignment of other big groups typically leads to stereopreference of one)ifmore than one βC has an available H the more substituted double bond will form first (i.e. take the H from
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