CHM1022 Lecture Notes - Lecture 2: Alkene, Van Der Waals Strain, Cyclohexane Conformation
13 Oct 2018
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Document Summary
When have the alkene need to consider about th e diastereoisomers (z)-1-bromo-2-methylpent-2-ene. Mechanism pro tips: arrows move from negative/nucleophiles to positive/ electrophiles. From nucleophiles: double bonds, lone pairs, negative ions, negative dipole. From electrophiles: positive ions, positive dipoles, positive atom in a molecule. Nb: the reaction happened in the water, which has extra water molecule. The twist relieves some of the torsional strain of the boat and moves the flagpole h further apart reducing the steric strain. Consequently the twist boat is slightly more stable than the boat. Ideally, a chair conformation that has its largest groups in equatorial position will be the most stable. When substituents are in the equatorial position, they are farther away from each other. In the pictures below, the methyl in the equatorial position is more stable because it avoids interaction with the hydrogen atoms. The larger the group is, the more it will tend to remain in the equatorial position.
