A research student is analyzing the completely unsymmetrical polyene 1-chloro-2,4-hexadiene (). Whic — Isomerism and Stereochemistry Chemistry Question
Question
A research student is analyzing the completely unsymmetrical polyene 1-chloro-2,4-hexadiene ($Cl-CH_2-CH=CH-CH=CH-CH_3$). Which of the following strict analytical statements regarding its stereoisomer calculation are definitively true?
💡 Solution & Explanation
The molecule ends in a chloromethyl group and a methyl group, rendering it completely unsymmetrical (no POS/COS possible), which immediately invalidates the formation of any meso forms (D is false). The molecule possesses exactly two stereogenic double bonds ($n=2$). Because it is unsymmetrical, the formula $2^n$ perfectly applies, yielding $2^2 = 4$ total geometrical stereoisomers.