有机化学⊙RGAnIc cⅫEMISTRY 盖饼：王德儒8709282901 理学院寇化素理科，2层206 Organic Chemistry,6th Edition L.G.Wade,Jr. Chapter 08 09 AlRenes Key Notes Electrophile;Electrophilic additionj Carbocation stability;Conjugated dienes Homework.:8-238-298-349-30:9-31b)(c)（P274)
Chapter 08 & 09 Alkenes Organic Chemistry, 6th Edition L. G. Wade, Jr. Key Notes Electrophile; Electrophilic addition; Carbocation stability; Conjugated dienes 有机化学ORGANIC CHEMISTRY 主讲：王俊儒 87092829(O) 理学院应化系理科楼2层C206 Homework：8-23; 8-29; 8-34; 9-30; 9-31(b), (c)（P274）
Content ☐Preparation ☐Reactions of alkenes -Electrophilic addition -Carbocation stabilization -Free-Radical Addition of HBr -Reduction and oxidation -Allylic halogenation ☐Conjugated dienes
Content ◼Preparation ◼Reactions of alkenes ◼Electrophilic addition ◼Carbocation stabilization ◼Free-Radical Addition of HBr ◼Reduction and oxidation ◼Allylic halogenation ◼Conjugated dienes
Sec 1 Alkenes structure and stability Molecule is planar around the double bond. The carbon atoms of the C=C bond are sp hybridized and Double bond is made up of one o bond and one πbond. Bond rotation round a C=C bond is not possible Isomers are possible depending on the substituents present. CH3 H. H. CH3 H3C cis no overlap with the ends perpendicular trans Copyright2010 Pearson Prentice Hall,Inc
Sec 1 Alkenes structure and stability ❑ Molecule is planar around the double bond. ❑ The carbon atoms of the C=C bond are sp hybridized and ❑ Double bond is made up of one bond and one bond. ❑ Bond rotation round a C=C bond is not possible ❑ Isomers are possible depending on the substituents present
Bond Lengths and Angles Pi overlap brings carbon atoms closer. Bond angle with pi orbital increases. .Angle C:=C-His121.7°；Angle H-C-His116.6° Cis and trans isomers cannot be interconverted. No rotation around the carbon-carbon 1.33 16.6° ethylene ethane
Bond Lengths and Angles ❖Pi overlap brings carbon atoms closer. ❖Bond angle with pi orbital increases. ◼Angle C=C-H is 121.7 ;Angle H-C-H is 116. 6 ❖Cis and trans isomers cannot be interconverted. ❖No rotation around the carbon—carbon
Cyclic Alkene Compounds cyclohexene cyclooctene trans-cyclodecene cis-cyclodecene Copyright2010 Pearson Prentice Hall,Inc. Trans cycloalkenes are not stable unless the ring has at least eight carbons. Cycloalkenes are assumed to be cis unless otherwise specifically named trans
Cyclic Alkene Compounds ❖Trans cycloalkenes are not stable unless the ring has at least eight carbons. ❖Cycloalkenes are assumed to be cis unless otherwise specifically named trans