Chapter 3 Structure and Properties Alkanes
stereoisomers produced by rotation (twisting) about σ bonds, and are often rapidly interconverting at room temperature
conformational isomer
CH3CH2Ch2OH CH3Ch2OCH3 CH3CH2CH3
Arrange the organic compounds from most soluble in water to least soluble in water.
2-methylhexane
Choose the molecule that has the higher boiling point. 2-methylhexane or 2,3-dimethylpentane
cyclohexane
Choose the molecule that has the higher boiling point. Hexane or Cyclohexane
2 3 180
How many gauche interactions are in the Newman projection at 180°? How many gauche interactions are in the Newman projection at 300°? Which is the most stable staggered conformation?
2,3‑dimethylbutane
IUPAC Name
The staggered Newman projection is most stable. The less gauche interactions, the more stable the Newman projection.
Identify the relative stability of each Newman projection.
Cyclopentane
Name
staggered, 3 gauche
Projection and gauche interactions
2‑methylpentane and 3‑methylpentane 2,3‑dimethylbutane and 2‑methylpentane
Which pairs of molecules are structural isomers? 2‑methylpentane and 3‑methylpentane hexane and 2‑methylhexane 2,3‑dimethylbutane and 2‑methylpentane 2‑methylpentane and 2‑methylhexane