organic chemistry - optical isomers Flashcards
the product formed exists as a racemic mixture
State the meaning of the tern racemic mixture and explain why such a mixture is formed in this reaction
a racemic mixture is a mixture with a 50:50 apply of enantiomers and so it is optically inactive (1 mark)
the PLANAR carbonyl group (1 mark)
attack from above or below so equal amounts of enantiomers are formed
state how separate samples of enantiomers could be distinguished
Shine plane polarised light through each sample
the light rotates differently/ in different directions by the same amount
by considering the shape of the reactive intermediate involved in the mechanism of this reaction
explain how a racemic mixture of the two stereoisomers of 2 - chlorobutane
the reactive carbocation is planar (1 mark) so they can be attacked from either side is equally likely
explain how E-Z isomerism arises
no free rotation about the C=C bond
use the displayed formula to explain why this molecule is optically active
the chiral centre is bonded to four DIFFERENT groups
what are the conditions for E - Z isomerism
two different functional groups on either side of a carbon double bond
