Question

Convert each ball-and-stick model to a skeletal structure that clearly shows the stereochemistry at the ring fusion of these decalin derivatives.

A.

B.

Short answer

A.

B.

Step-by-step solution

 Ball and stick model

The three-dimensional location of the atom and the bonds can be displayed using the molecular model termed the ball-and-stick model.Two or three curved rods are used to indicate double or triple bonds.

Skeletal structure

Skeletal structures constitute an important part of organic chemistry. The skeletal structure of a particular compound is displayed using a skeletal formula, also termed the shorthand formula.

Conversion of the given ball-and-stick model to a skeletal structure

Decalin and its derivatives comprise a six-membered ring that shares a C-C bond. The substituents present at the ring fusion are classified as cis or trans.

If the substituents present at the ring fusion are opposite to each other, it is indicated as trans. If the substituents are located on the same side, it is indicated as cis.

a.The skeletal structure of this decalin is:

Skeletal structure of compound a

Since the substituents at the ring fusion are present on the same side, the given structure is cis-decalin.

b.The skeletal structure of this decalin is:

Skeletal structure of compound b

Since the substituents at the ring fusion are present on the opposite side, the given structure is trans-decalin.