How to Understand the Merits and Demerits of Different Projections of a Molecule – Part 2

Projection is a two-dimensional (2D) representation of a three-dimensional (3D) organic molecule.


The Newman projection visualizes the conformation of a chemical bond from front to back, with the front atom (proximal) represented by the intersection of three lines (a dot) and the back atom (distal) as a circle and clearly illustrates the specific dihedral angle between the proximal and distal atoms.

The Fischer projection is a 2D representation of a 3D organic molecule by projection.

The Natta projection (wedge-dash) is a way to project 3D organic molecules with complete stereochemistry in 2D in a skeletal formula.

There are more types of projections, viz., sawhorse projection, Mills projection & Haworth projection. Each projection in stereochemistry has their own pros and cons.

A molecule's R/S labeling (absolute configuration) is done using the CIP (Cahn-Ingold-Prelog) priority rules.

The Newman projection is not quite compatible to using the CIP rules. Hence, it should be converted to the Fischer projection for the absolute configuration assignment.

Question:

Which of the following is (R)-Hexan-3-ol?



Click/tap to enlarge the image

Solution infographic:



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Pragmatic projections❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗

References:

(1)    Ncert. Chemistry : Textbook for Class XI - Part.II; National Council Of Educational Research And Training: New Delhi.

(2)    Graham, T. W.; Fryhle, C. B.; Snyder, S. A. Organic Chemistry.; Hoboken, Nj John Wiley Et Sons, Inc, 2016.

(3)    Brown, C.; Ford, M. Higher Level Chemistry, 2nd ed.; Pearson Education: Harlow, Essex, 2014.

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