Relative Stabilities cumulated terminal diene alkyne C- twice 1-pentene 1.2-pentadiene I-pentyne internal alkyne 292kJ 2-pentyne more substituted (69.8 kcal) isolated 291kJ diene (69.5 keal) isolated 275kJ 1.4-pentadiene diene (65.8kcl trans-1.4-hexadiene conjugated 252kJ diene (60.2 keal) 242kJ trans-1,3-pentadiene (57.7 kcal) 225kJ (53.7kcal) alkane (pentane or hexane) Copyright 2010 Pearson Prentice Hall,Inc. Chapter 15 4 Chapter 15 4 Relative Stabilities twice 1-pentene more substituted