Calculate the total number of distinct geometrical isomers possible for the linear, unsymmetrical po — Isomerism and Stereochemistry Chemistry Question
Question
Calculate the total number of distinct geometrical isomers possible for the linear, unsymmetrical polyene chain given by the structure: $C_6H_5-CH=CH-CH=CH-CH=N-OH$.
💡 Solution & Explanation
The molecule contains 3 stereogenic centers capable of restricted rotation and Geometrical Isomerism: two $C=C$ double bonds and one $C=N$ imine/oxime bond ($n=3$). Because the terminal structural ends of the chain are entirely different (a Phenyl group vs. an $-OH$ group), the molecule is stereochemically unsymmetrical. The formula for unsymmetrical systems is $2^n$. Therefore, $2^3 = 8$ total geometrical isomers exist.