Question

question 5
what is the stretching frequency (in cm⁻¹) of the following carbonyl?
none of the above
1685
1715
1745

Explanation:

Step1: Identify carbonyl type

The given is a cyclic ketone. Ring - strain affects carbonyl stretching frequency. Smaller rings have higher - energy carbonyls.

Step2: Recall frequency range

Cyclic ketones with ring - strain (such as cyclopropanone) have carbonyl stretching frequencies around 1745 cm⁻¹ due to increased ring - strain.

Answer:

1745