The 1,5-sigmatropic rearrangements involving group (X) migration in ${omega}$(X)-substituted 1,3-pentadiene, $C^1H_2=C^2H-C^3H=C^4H-C^5H_2-X$, where X = H, $CH_3$, $BH_2$, $NH_2$, OH or F, are investigated MO theoretically using the AM1 method. For the migrating groups without lone pair electrons, X = H, $CH_3$, or $BH_2$, the suprafacial pathway is favored, whereas for the migrating groups with lone pair electrons participating in the TS, $X=NH_2$, OH, or F, the antarafacial pathway is favored electronically. However excessive steric inhibition in the antarafacial TS for $X=NH_2$ leads to subjacent orbital controlled suprafacial process. The antarafacial shift of F is relatively disfavored compared to that of OH due to smaller orbital overlap and larger interfrontier energy gap in the TS.