8.7A Syn addition of hydrogen Synthesis of cis-alkenes NabH4 Ni(oCoCH3)2 Ni,B (P-2) CH3CH2OH Syn addition H3C CH Ni,B(P-2)H H Syn addition c CH3 Pd/CacO3, quinoline (Lindlar's catalyst)
8.7A Syn addition of hydrogen: Synthesis of cis-alkenes Ni(OCOCH3 ) 2 NaBH4 CH3 CH2OH Ni 2 B (P-2) + H2 H3 C H CH3 H Syn addition Ni 2 B (P-2) + H2 H3C H CH3 H Syn addition Pd/CaCO3 , quinoline (Lindlar's catalyst)
8.7b Anti addition of hydrogen Synthesis of trans-alkenes anti addition 1. Li. Ch CHNH H3C H 2, NH4CL, -78C H CH (E)-2-Butene a /NH3o H3C H anti addition H CH 3 (E)-2-Butene
8.7B Anti addition of hydrogen: Synthesis of trans-alkenes H3 C H H CH3 anti addition 1, Li, CH3 CH2 NH2 2, NH4 Cl, -78 o C (E)-2-Butene H3 C H H CH3 anti addition Na / NH3 (l) (E)-2-Butene
8.9 Relative stabilities of alkenes 8.9A Heats of hydrogenation H3C CH3 H30 CH3CH2 CH=CH2+ H H +H H H CH 3 2 旨|△H°=-30.3 kcal mol1 △H=-286 kcal mol-1 △H .27.6 kcal mol CH3 CH3 CH3 CH2CH2CH CH3 CH2 CH2CH3
8.9 Relative stabilities of alkenes 8.9A Heats of hydrogenation CH3CH2CH=CH2 + H2 H3C H CH3 H H3C H H CH3 + H2 + H2 H o = -30.3 kcal mol -1 H o = -28.6 kcal mol -1 H o = -27.6 kcal mol -1 CH3CH2CH2CH3 CH3CH2CH2CH3 CH3CH2CH2CH3 Potential energy
The order of stabilities H3c HRc CHr CHCH=CH CH3 H
H3C H H CH3 H3C H CH3 H CH3CH2CH=CH2 The order of stabilities;