In a 3D Wedge-Dash projection, if the lowest priority substituent (Group 4) is incorrectly located o — Isomerism and Stereochemistry Chemistry Question
Question
In a 3D Wedge-Dash projection, if the lowest priority substituent (Group 4) is incorrectly located on the solid wedge (pointing directly at the observer), what immediate mathematical adjustment must be made after tracing the $1 \rightarrow 2 \rightarrow 3$ path?
💡 Solution & Explanation
If Group 4 is on a solid wedge, it is pointing toward the viewer, violating the standard viewing perspective required by IUPAC rules. The established shortcut dictates tracing the $1 \rightarrow 2 \rightarrow 3$ priority path as it appears, and then strictly reversing the final result. Therefore, if the trace appears anti-clockwise (S), the actual configuration is genuinely 'R'.