When translating a 3D structure into a 2D Fischer Projection, vertical lines represent bonds project — Isomerism and Stereochemistry Chemistry Question

💡 Solution & Explanation

In the specialized geometry of a Fischer projection, vertical lines strictly represent bonds plunging backward into the page (identical to a dashed wedge). Because Group 4 is situated on a vertical line, it is in the ideal position. Thus, the $1 \rightarrow 2 \rightarrow 3$ trace is completely valid, and a clockwise path yields an 'R' configuration without any necessary reversal.