What is the general structural formula of an ester?

What is the general structural formula of an ester?

• A. R-NH2
• B. R-COO-R
• C. R-O-R
• D. R-CN

Answer: (B)

Esters are defined by a carbonyl carbon bonded to an alkoxy group, giving the general formula R-COO-R'. The carbonyl carbon carries a double bond to oxygen and a single bond to an oxygen that connects to another alkyl (or aryl) group. This O–R' linkage is what sets esters apart from other functional groups: an amine would have an -NH2 group, a simple ether would lack the carbonyl (R-O-R), and a nitrile would feature a carbon triple-bonded to nitrogen (R-CN). A concrete example is ethyl acetate, CH3-CO-O-CH2-CH3, illustrating the carbonyl attached to an -O- that connects to another carbon-containing group. Thus, the general structural formula is R-COO-R'.

Esters are defined by a carbonyl carbon bonded to an alkoxy group, giving the general formula R-COO-R'. The carbonyl carbon carries a double bond to oxygen and a single bond to an oxygen that connects to another alkyl (or aryl) group. This O–R' linkage is what sets esters apart from other functional groups: an amine would have an -NH2 group, a simple ether would lack the carbonyl (R-O-R), and a nitrile would feature a carbon triple-bonded to nitrogen (R-CN). A concrete example is ethyl acetate, CH3-CO-O-CH2-CH3, illustrating the carbonyl attached to an -O- that connects to another carbon-containing group. Thus, the general structural formula is R-COO-R'.