Question

The IUPAC name of the compound is

• A. 3-Methylspiro[5∙4]dec -2-ene
• B. 2-Methylspiro[4∙5]dec-1-ene
• C. 3-Methylspiro[4∙5]dec-2-ene
• D. 2-Methyspiro[5∙4]dec-1-ene

Answer 1

The correct option is B

2-Methylspiro[4∙5]dec-1-ene

The carbon atoms of the given compound are numbered as below:

Total number of carbon atoms =10 (word root = dec)

There is a double bond between $C_{1}and{C}_2$

Further, there is a methyl $(-C{H}_3)$ substituent at $C_2$.

Hence the IUPAC name is

(B) 2-Methylspiro[4,5]dec-1-ene