Q.30-12 - Organic Chemistry (Mcmurry)

Question

The ¹³C NMR spectrum of homotropilidene taken at room temperature shows only three peaks. Explain.

Step-by-Step Solution

Answer

The ¹³C NMR spectrum of homotropilidene taken at room temperature shows only three peaks can be explained.

Three distinct types of carbon

There is a rearrangement of homotropilidene at a rate is too fast for detection of NMR. The ¹³C NMR spectrum taken at the room temperature for the average of 2 equilibrating forms for the equivalent position as 1 and 5 as are position 2 and 4. There are three distinct types of carbon are visible in the spectrum of ¹³CNMR of homotropilidene.

Five peaks at the spectrum of homotropilidene

The ¹³C NMR spectrum of homotropilidene will show 5 peaks when rearrangement were slow. It will show only 3 peaks at room temperature due to its average of two equilibrating form of specific positions.