Question

what is the classification of each labeled carbon atom in this structure? c1 is a 2°, c2 is 3°, c3 is a 3°, and c4 is 4°. c1 is a 2°, c2 is 3°, c3 is a 3°, and c4 is 3°. c1 is a 2°, c2 is 3°, c3 is a 3°, and c4 is 4°. c1 is a 1°, c2 is 2°, c3 is a 3°, and c4 is 4°. c1 is a 2°, c2 is 3°, c3 is a 2°, and c4 is 3°. c1 is a 1°, c2 is 2°, c3 is a 3°, and c4 is 1°.

Explanation:

Step1: Recall carbon - atom classification rules

A primary carbon ($1^{\circ}$) is bonded to one other carbon atom, a secondary carbon ($2^{\circ}$) is bonded to two other carbon atoms, a tertiary carbon ($3^{\circ}$) is bonded to three other carbon atoms, and a quaternary carbon ($4^{\circ}$) is bonded to four other carbon atoms.

Step2: Analyze C1

C1 is bonded to two other carbon atoms in the ring structure, so C1 is a $2^{\circ}$ carbon.

Step3: Analyze C2

C2 is bonded to three other carbon atoms (two in the ring and one outside - the methyl group), so C2 is a $3^{\circ}$ carbon.

Step4: Analyze C3

C3 is bonded to three other carbon atoms (two in the ring and one outside - the methyl group), so C3 is a $3^{\circ}$ carbon.

Step5: Analyze C4

C4 is bonded to four other carbon atoms, so C4 is a $4^{\circ}$ carbon.

Answer:

C1 is a $2^{\circ}$, C2 is $3^{\circ}$, C3 is a $3^{\circ}$, and C4 is $4^{\circ}$