Question

The correct IUPAC name of the following structure is :

• A. 1-(but-2-enyl)-cyclobuta-1,4-diene
• B. 1-(1,3-cyclobutyl)-prop-3-ene
• C. 3-(1,3-cyclobutyl)-prop-1-ene
• D. 1-(prop-2-enyl)-cyclobuta-1,3-diene

Answer 1

The correct option is D 1-(prop-2-enyl)-cyclobuta-1,3-diene

Rules for determining the parent chain:
Case A:
If the ring has unsaturation and the open chain is saturated, then,
Ring - Parent Chain
Open Chain - Substituent

Case B : If both the open chain and the ring have unsaturation, then
Chain with maximum unsaturation is taken as parent chain.
Here, ring has more saturation than open ring, so ring is taken as parent chain .
Double bond is given priority while numbering.


So, the correct IUPAC name of the structure is
1-(prop-2-enyl)-cyclobuta-1,3-diene