EX:Antiviral medicines can prevent flu-N&O(People's Pharmacy)January 1,2004 Oral anti-flu medications are not numerous.One of the first was a drug "Symmetrel"originally developed to treat Parkinson's Disease(1966),but approved by the FDA for flu ten years later.A related compound, Rimantadine received approval in 1993.Both must be taken within the first day or two of the flu,and are effective only against strains of Type A influenza.(135种类型) C12H21N NH2 C1oH17N The News Observer -NH2 金刚胺 Rimantadine Amantadine 金刚烷胺 aka Flumadine aka Symmetrel 去冬以来国内16个省现人感染H7N9禽流感病例，至今1月公开数据显示， 有200多人发病，80余人死亡。这也是2013年首次发现H7N9禽流感病毒以 来，最为严重的一次疫情。近日中国工程院院士钟南山表示，H7N9病毒变 异株已现耐药性，呼吁不要接触活禽。 禽流感.达菲.莽草酸.八角
EX: Antiviral medicines can prevent flu –N&O (People’s Pharmacy) January 1, 2004 Oral anti-flu medications are not numerous. One of the first was a drug “Symmetrel” originally developed to treat Parkinson’s Disease (1966) , but approved by the FDA for flu ten years later. A related compound, Rimantadine received approval in 1993. Both must be taken within the first day or two of the flu, and are effective only against strains of Type A influenza. (135种类型 ) 金刚胺 金刚烷胺 The News & Observer 禽流感…达菲…莽草酸…八角 去冬以来国内16个省现人感染H7N9禽流感病例，至今1月公开数据显示， 有200多人发病，80余人死亡。这也是2013年首次发现H7N9禽流感病毒以 来，最为严重的一次疫情。近日中国工程院院士钟南山表示，H7N9病毒变 异株已现耐药性，呼吁不要接触活禽
Cis-Trans Isomerism H.C CH3 H CH3 cis-2-butene trans-2-butene CH3 H令令H H,C令H CHCH3 CH3 CH3 H CH H CH3 cis-1,2-dimethylcyclopentane trans-1,2-dimethylcyclopentane -Cis:like groups on same side of ring -Trans:like groups on opposite sides of ring
Cis-Trans Isomerism ▪Cis: like groups on same side of ring ▪Trans: like groups on opposite sides of ring
Sec 2 Stability of Cycloalkanes:Ring Strain Angle strain The strain induced in a molecule when bond angles are forced to deviate from the ideal 109 tetrahedral value(Adolf von Baeyer-1885) 1og°tetrahedral 199 499 90° 108 20° 601 Cyclopropane Cyclobutane Cyclopentane Cyclohexane eLeingAlihRered
Angle strain ▪ The strain induced in a molecule when bond angles are forced to deviate from the ideal 109º tetrahedral value (Adolf von Baeyer – 1885) Sec 2 Stability of Cycloalkanes: Ring Strain
Stability of Cycloalkanes:Ring Strain Angle strain Experimental data show that Baeyer's theory is only partially correct 120 28.7 100 23.9 80 19.1 60 14.3 9.6 0 4.8 0 34567891011121314 Ring size oC. Baeyer assumed all cycloalkanes to be flat Angle strain occurs only in small rings that have little flexibility
Angle strain ▪ Experimental data show that Baeyer’s theory is only partially correct ▪ Baeyer assumed all cycloalkanes to be flat ▪ Angle strain occurs only in small rings that have little flexibility Stability of Cycloalkanes: Ring Strain
Stability of Cycloalkanes:Ring S Strain The three kinds of strain that contribute to the overall energy of a cycloalkane: 1.Angle strain-the strain due to expansion or compression of bond angles 2.Torsional strain-the strain due to eclipsing of bonds on neighboring atoms 3. Steric strain-the strain due to repulsive interactions when atoms approach each other too closely eclipsed H's eclipsed H's eclipsed H's 12:side view of cyclopropane
The three kinds of strain that contribute to the overall energy of a cycloalkane: 1. Angle strain – the strain due to expansion or compression of bond angles 2. Torsional strain – the strain due to eclipsing of bonds on neighboring atoms 3. Steric strain – the strain due to repulsive interactions when atoms approach each other too closely Stability of Cycloalkanes: Ring Strain