91Ó°ÊÓ

The Fischer projection is a two-dimensional representation of a molecule using horizontal and vertical lines.

It is generally used for molecules with a chiral center. The chiral center is represented as a cross in the Fischer projection.

In Fischer projection, the bonds above the plane are represented by horizontal lines, and the bonds below the plane are represented by vertical lines.

To convert a ball-and-stick model into Fischer projection, rewrite the skeletal compound using dashed and wedge bonds.

Rotate the molecule such that the end carbon occupies the top and bottom positions.

Identify the conformation of the compound. If it is in staggered conformation, convert it into eclipsed form.

Identify the bonds that are out of a plane and its direction from the plane.

Construct the Fischer projection with bonds in the same direction on the same side of the vertical line.

Convert the molecule into its skeletal form. In the figure, A gives the skeletal form of the molecule. The compound is given in staggered form. Therefore, convert the molecule into its eclipsed form.

Conversion to eclipsed form

Redraw the eclipsed form so that all bonds to H and OH on stereogenic carbon are shown with wedges in C are on the right side of the vertical line and dashed bonds in C on the left.

Finally, replace the wedges with crosses to get the Fischer projection of the compound.

Fischer projection of compound