11.2 Terminology Describing Stereochemistry

11.2 Terminology Describing Stereochemistry

• Use the information provided to draw the product that you expect.

• Special terminology is used to describe the stereochemistry of a reaction.

• We know which two groups are adding to the double bond.
• We need to know the stereochemistry of the reaction in order to draw the products correctly.
• In a different way, we will explain this.

• 2 were hybridized and trigonal.

• All four groups are connected to the same plane.

• This way of drawing the alkene will make it easier to explore stereochemistry, since all bonds are shown as wedges and dashes.

• The regiochemistry is described by Markovnikov.
• We will see such an example very soon.

• There are four possible products.

• Some reactions are not stereospecific, and we might expect all four possible products.
• The mechanism for each reaction will always explain the stereochemistry of the reaction as we go through each reaction in this chapter.
• Let's make sure we know what we're talking about.
• When all of the information has been provided, we will practice drawing the products.

• The examples we have seen so far are not containing a ring.
• The products are easier to draw because we don't have to change the alkene before starting.

• The regiochemistry is the first thing we look at.
• Markovnikov means that the OH group will be positioned at the less substituted carbon.
• The products are easy to draw since the alkene is a cyclic compound.

• There are examples where no stereocenters are being formed.

• Stereochemistry is irrelevant in situations like this.
• There is one product.

• Stereochemistry is irrelevant if the compound doesn't have any other stereocenters.
• There are only two possible products with only one stereocenter.
• A racemic mixture is obtained.

• The regiochemistry is the first thing we look at.
• We are not told what the regiochemistry is because it is irrelevant.
• Stereochemistry is looked at next.

• If the reaction had not been stereospecific, we would have obtained the same two products.

• We are close to learning the reactions.
• We need to explore one more aspect of the stereochemistry of addition reactions.

• There aren't two products here.
• The two drawings above are the same compound.
• There is only one product in this case.
• You can either use both OH groups on wedges or use both OH groups on dashes.
• You are drawing the same thing.

• Three groups are rotating in space.

• This is an important point.

• The regiochemistry is the first thing we look at.
• The regiochemistry is irrelevant in this case because we are adding two groups of the same kind.

• Stereochemistry is looked at next.
• We don't have to change the alkene to draw this pair of enantiomers.

• In this case, we have a plane of symmetry, because we look for a plane of symmetry.
• We don't draw the drawings above as our answer.
• We have one drawing to choose from.

• Predict the products using the information provided.