Exo%2fEndo

Exo%2fEndo - Endocyclic and exocyclic double bonds: In the...

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Endo-Exo Convention 1) the position of double bonds relative to rings in carbocyclic systems; 2) the relative orientation of substituents of bridged carbocycles; 3) opposing pathways for certain intramolecular cyclization and cleavage reactions; 4) opposing pathways for Diels-Alder type cycloaddition reactions based on the orientation of dienes to dieneophiles.
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endocyclic exocyclic Alkene Orientations Ring Bridging 1) a bridge containing a heteroatom or atoms 2) a shorter bridge 3) a saturated bridge 4) a less substituted bridge 5) a bridge with the lowest CIP priority substituents
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O W W O W W CH 3 CH 3 W W O W W HO CH 3 endo endo exo exo exo exo endo endo
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INTRAMOLECULAR CYCLIZATIONS endocyclic addition exocyclic addition
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Example 1.
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Unformatted text preview: Endocyclic and exocyclic double bonds: In the compound chamigrene, which was stereoselectively synthesized by transannular cyclopropanation followed by ring fragmentation, there is both an endocyclic double bond and an exocyclic double bond Example 2 . 2,6-Dimethylbicyclo[3.3.1]nona-3,7-diene-endo-2,endo-6-diol. The short bridge takes precedence over the unsaturated bridges H 3 C HO CH 3 OH For each bridged compound below, identify the reference bridge and specify the endo/exo orientation of "W" substituent NH W NH 2 O W O W OEt Br OH H 3 CO W H 3 C CH 3 W W H 3 C CH 3 W H 3 C CH 3 HO W COOH O W (a) (b) (d) (h) (f) (c) (e) (g) (i)...
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Exo%2fEndo - Endocyclic and exocyclic double bonds: In the...

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