BAEYER'S STRAIN THEORY PRESENTATION.pptx

This presentation contains brief summary of Baeyer's strain theory.

1. ITM UNIVERSITY JHANSI ROAD, TURARI, GWALIOR, M.P SESSION : 2021-2022 COURSE : B.PHARMA YEAR : SEMESTER : SUBJECT : PHARMACEUTICAL ORGANIC CHEMISTRY - II TOPIC : CYCLOALKANES SUB - TOPIC : BAEYER’S STRAIN THEORY AND ITS LIMITATIONS   REPRESENTED BY:- SHREYA ANANTA (BPYN1PY20028)

2. ACKNOWLEDGEMENT I would like to express my special thanks of gratitude to our pharmaceutical organic chemistry-II professor respected “ Mrs. Divya Niranjan” ma’am who gave us the golden opportunity to do this wonderful presentation on topic “ Baeyer’s theory and its limitations” which also helps us in doing a lot of research and I come to know about so many things. I am really thankful to you. It helped me to increase my knowledge and skills.

3. CONTENT INTRODUCTION OF BAEYER’S STRAIN THEORY ASSUMPTION OF BAEYER’S STRAIN THEORY LIMITATIONS OF BAEYER’S STRAIN THEORY CASE STUDY ON BAEYER’S STRAIN THEORY REFERENCES

4. INTRODUCTION OF BAEYER’S STRAIN THEORY Adolf von Baeyer, a German chemist and a Nobel prize winner from university of Munich, Germany in 1885 proposed a theory to explain the relative stability of the first few cycloalkane. The theory based on following facts: 1. Cyclo-alkanes are saturated compounds. So, all the carbons should have normal tetrahedral angle of 2. Any deviation of bond angles from the normal tetrahedral value would, impose a condition of internal strain on the ring called angle strain. 3. More the value of angle strain less stable the compound is. 4. He assumes that all the cyclo-alkanes are flat and coplanar that means they are two dimensional and present in one plane.  

5. ASSUMPTIONS OF BAEYER’S STRAIN THEORY All ring systems are planar. Deviation from normal tetrahedral angles results in to instable cycloalkanes. The large ring systems involve negative strain hence do not exists. The bond angles in cyclohexane and higher cycloalkanes (cycloheptane, cyclooctane, cyclononane, etc.) are not larger than because the carbon rings of those compounds are not planar (flat).  

6. LIMITATIONS OF BAEYER’S STRAIN THEORY Baeyer was not able to explain the effect of angle strain in larger ring systems. According to Baeyer Cyclopentane should be much stable than cyclohexane but practically it is reversed. Larger ring systems are not possible according to Baeyer as they have negative strain but they exist and much stable. Larger ring systems are not planar but wrinkled (puckered) to eliminate angle strain.

7. CASE STUDY ON BAEYER’S STRAIN THEORY According to Baeyer, the relative order of stability for some common cycloalkanes is as under: Cyclopentane Cyclohexane Cyclobutane Cyclopropane Actual observed order of stability for these cycloalkanes is as under: Cyclohexane > Cyclopentane > Cyclobutane > Cyclopropane  

8. REFERENCES www.slideshare.net https://staticscience.com http://www.researchgate.net http://www.vpscience.org THANK YOU