Chemistry 2100 Lecture 2
Alkynes and Alkenes alkene (olefins): CnH2n alkyne (acetylenes): CnH2n-2 Ethene Ethyne Ethylene Acetylene
Naming Alkenes and Alkynes Parent name is that of the longest chain that contains the C=C or C≡C. Number the chain from the end that gives the lower numbers to the carbons of the C=C or C≡C. Locate the C=C or C≡C by the number of its first carbon. Use -ene to show C=C, -yne for C≡C. For cycloalkenes: Number ring carbons to give carbon 1 and 2 to the C=C bond. Because of this convention, no need to specify the number of the C=C.
Alkene Isomerism 3-methyl-cis-2-pentene 3-methyl-trans-2-pentene 2-methyl-2-pentene
Conjugation
2
trans-retinal
trans-retinal
trans-retinal
trans-retinal 11-cis-retinal
opsin
opsin
opsin
opsin rhodopsin
rhodopsin metarhodopsin
rhodopsin metarhodopsin
rhodopsin metarhodopsin
rhodopsin neural impulse metarhodopsin
neural impulse metarhodopsin 11-cis-retinal trans-retinal
neural impulse metarhodopsin 11-cis-retinal trans-retinal
neural impulse metarhodopsin 11-cis-retinal trans-retinal
neural impulse metarhodopsin 11-cis-retinal trans-retinal opsin
neural impulse metarhodopsin 11-cis-retinal trans-retinal opsin
Terpenes – natural polyenes limonene (orange, dill) myrcene (bay) geraniol (rose) menthol (mint) carvone (spearmint, dill) zingiberene (ginger) -selinene (celery) caryophyllene (cloves)
squalene
squalene ~25 steps lanosterol cholesterol
Making Alkenes tetra tri di mono
Reactions of Alkenes Hydrogenation (cis or trans)
Partially Hydrogenated Vegetable Oil •
Halogenation CH2Cl2 RT ∆ / h Cl2 CH2Cl2
Acid Addition CH2Cl2 minor major H2SO4
Polymerization Z = CH3 polypropylene polypropylene Z = Cl PVC PVC Z = CN polyacrylonitrile Z = OH polyvinyl alcohol polypropylene PVC polyacrylonitrile polyvinyl alcohol
Polymers & Health Bisphenol A = hard shell plastic Pthalate, plasticizer