A student has just added ammonia to hexanoic acid and has begun to heat the mixture when he is called away to the telephone. After a long telephone conversation, he returns to find that the mixture has overheated and turned black. He distills the volatile components and recrystallizes the solid residue. Among the components he isolates are compounds A (a liquid; molecular formula C₆H₁₁N) and B (a solid; molecular formula C₆H₁₃NO). The infrared spectrum of A shows a strong, sharp absorption at 2247 cm^-1. The infrared spectrum of B shows absorptions at 3390, 3200, and 1665 cm^-1. Determine the structures of compounds A and B.