Question

The IUPAC name of is

• A. Spirocyclopropylcyclohenane
• B. Spiro[6∙2]octane
• C. Spiro[5∙2∙0]octane
• D. Spiro[2∙5]octane

Answer 1

The correct option is D

Spiro[2∙5]octane

The given compound is a spiro compound is the same as

The numbering proceeds to give the lowest possible numbers to the smaller bridge, starting with the ring atom next to the common atom.

Hence is the correct approach to numbering the carbon atoms of the compound excluding the common carbon atom,

the smaller bridge has 2 carbon atoms while the large bridge has 5 carbon atoms.

Hence the IUPAC name is Spiro[2.5]octane.