Name: Diastereomers and Meso Compounds
Uploaded: 2019-07-19
Duration: 10 min 31 s
Description: Here, we will see how compounds with multiple stereocenters may be achiral if they have an internal plane of symmetry or an inversion centre. Let's explore.

Question

Explain the following combination of axial and equatorial bonds with cis or trans orientation for $1, 3 -$ dimethyl cyclohexane

$1 e, 3 e$

Accepted Answer

For $1, 3 -$ dimethyl cyclohexane substrate two methyl groups will be added on chair conformation of cyclohexane systematically as follows $1 e, 3 e$

Stability of chair conformation $: -$

Since cyclohexane ring is alicyclic ring, so here there are $4$ possible conformational structures out of which chair conformational form is the most stable due to strain free structure called puckered chair conformation.

Chair $>$ Twist boat $>$ boat $>$ half chair

So, it is confirmed that the given substrate exist in chair conformation.

Concept of axial and equatorial position $: -$

The methyl substituent if present on cyclohexane ring at perpendicular position to plane of chair conformation then that is called axial position. If methyl substituent is approx parallel and present along with axial position then that is called equatorial position.

Drawing of chair conformation with methyl substituent $: -$

Draw a chair form and add $1$ methyl at equatorial position and other methyl group also at equatorial position in $1, 3 -$ condition.

Confirmation of relative stereochemistry $: -$

Here, $2$ methyl groups are lying on the same side at dihedral angle of $60 \to 120$ degree in gauche staggered conformation, so the written structure is trans or anti. Hence, this combination will be determined as trans $- 1, 3 -$ dimethyl cyclohexane in terms of stereochemistry.

Explain the following combination of axial and equatorial bonds with cis or trans orientation for $1, 3 -$ dimethyl cyclohexane

$1 e, 3 e$

Important Questions on Isomerism

Learn and Prepare for any exam you want !

Explain the following combination of axial and equatorial bonds with cis or trans orientation for 1,3-dimethyl cyclohexane 1e, 3e

Important Questions on Isomerism

Learn and Prepare for any exam you want !

Explain the following combination of axial and equatorial bonds with cis or trans orientation for $1, 3 -$ dimethyl cyclohexane

$1 e, 3 e$