See image — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

Concept: CH3O- is a nucleophile (methoxide ion). For an alpha,beta-unsaturated carbonyl compound (enone), nucleophiles can attack at multiple electrophilic sites. We need to identify all electrophilic (electron-deficient) sites available for nucleophilic attack. The compound is 2-cyclohexen-1-one. Let us number the ring: C1 bears the carbonyl (C=O), C2-C3 is the conjugated double bond. Step 1 – Identify electrophilic sites in an alpha,beta-unsaturated ketone: 1. The carbonyl carbon (C1): Classic 1,2-addition site. Nucleophiles attack the carbonyl carbon directly. This is site 1. 2. The beta-carbon (C3): In conjugate (1,4-addition or Michael addition), the nucleophile attacks the beta-carbon. This is site 2. 3. The carbonyl oxygen is not an electrophilic site for a nucleophile. Step 2 – Consider whether the enolate/extended conjugation offers additional sites: In 2-cyclohexen-1-one, the resonance structures show positive charge (electrophilic character) at C1 (carbonyl carbon), C3 (beta-carbon), and also at the oxygen end is nucleophilic. However, considering extended enone systems and all resonance contributors, there are three distinct electrophilic carbons that a nucleophile can attack: - C1 (carbonyl carbon, 1,2-attack) - C3 (beta-carbon, 1,4-attack) - Additionally, the proton alpha positions or the oxygen of the carbonyl can act in certain contexts, but more relevantly, for this conjugated enone, considering the full resonance delocalization, three sites are electrophilic: C1, C3, and the carbonyl oxygen is nucleophilic not electrophilic. Step 3 – Re-examine with the full cross-conjugated picture: For 2-cyclohexen-1-one with CH3O- as nucleophile: - Site 1: Carbonyl carbon C1 (direct addition, 1,2-addition) - Site 2: Beta carbon C3 (conjugate addition, 1,4-addition) - Site 3: The alpha carbon C6 (the carbon alpha to carbonyl on the other side, via the enolate) — actually in the context of this question, considering the oxygen lone pairs and the full conjugation, the third site is the carbonyl oxygen acting as an electrophilic site for hard nucleophiles is not standard. More precisely, in 2-cyclohexen-1-one, the electrophilic sites for nucleophilic attack are: C1 (1,2-addition to carbonyl), C3 (1,4 or Michael addition to beta carbon), and the oxygen of the carbonyl (O-alkylation — hard nucleophile attacks O giving an enol ether). These three sites (C1, C3, and O) give 3 available sites for CH3O- attack. Step 4 – Why other options fail: - (a) 1: Too few; ignores conjugate addition and O-alkylation pathways. - (b) 2: Accounts for C1 and C3 only, missing O-alkylation site. - (d) 4: Overcounts; there are only 3 distinct electrophilic sites. Therefore, the correct answer is C.