1-cyclopropylethyne has a triple bond:
Hence it seems like it should yield a positive unsaturation test with bromine water. But, my book states that the opposite is true.
I guess this may be due to steric crowding on the C atom bearing the cyclopropyl ring, but I'm not sure.
What is the exact reason that 1-cyclopropylethyne does not yield a positive bromine water unsaturation test?