Problem 25 - Chemistry The Central Science

Question

Enediynes are a class of compounds that include some antibiotic drugs. Draw the structure of an "enediyne" fragment that contains six carbons in a row.

Step-by-Step Solution

Answer

The structure of an enediyne fragment containing six carbon atoms in a row can be drawn as follows: H H H H H | | | | H-C-C≡C-C=C-C-H | | H H H

Step 1: Draw the carbon chain

First, we need to draw a chain of six carbons in a row. To do this, draw six vertical lines representing each carbon atom, connected by single bonds.

Step 2: Add the triple bond

A triple bond consists of one sigma bond and two pi bonds. In the enediyne structure, the triple bond occurs between the second and third carbon atoms from the left. To represent the triple bond, draw two additional lines parallel to the single bond between the second and third carbon atoms.

Step 3: Add the double bond

A double bond consists of one sigma bond and one pi bond. In the enediyne structure, the double bond occurs between the fourth and fifth carbon atoms from the left. To represent the double bond, draw one additional line parallel to the single bond between the fourth and fifth carbon atoms.

Step 4: Complete the molecule with hydrogen atoms

Since each carbon in the enediyne fragment forms four bonds, we need to add hydrogen atoms to complete the structure. For the first carbon atom, add three hydrogen atoms. For the second and third carbon atoms (which are connected by a triple bond), add only one hydrogen atom each. For the fourth and fifth carbon atoms (which are connected by a double bond), add two hydrogen atoms each. Finally, for the sixth carbon atom, add three hydrogen atoms. The completed structure of the enediyne fragment should look like this: H H H H H | | | | H-C-C≡C-C=C-C-H | | H H H