Dr. Anand S. Burange

BAEYER STRAIN THEORY AND STRAIN Anand S. Burange, Wilson College, Mumbai asgburange@gmail.com. Small rings like cyclopropane and cyclobutane have larger values of heat of combustion per –CH 2 - group compared to other larger rings. The answer to this observation lies in a theory proposed by Adolf Von Baeyer from University of Munich in 1885. His theory is also known as Baeyer’s Strain Theory but all the aspects discussed in theory are not completely accepted as some of them were proven wrong in the course of history. Now a days this theory, is modernized and then discussed for the better understanding of students/researchers. Baeyer’s Strain Theory Assumptions: Baeyer in his theory, he did few arguments where he failed to convince many aspects while some of them are well accepted. Few important arguments from his theory are as follows. # Argument 1 In cyclopropane and cyclobutane, all carbon atoms are SP 3 hybridized therefore expected bond angle (C-C-C bond angle) s...

CYCLOHEXANE STEREOCHEMISTRY Anand S. Burange, Wilson College, Mumbai asgburange@gmail.com Cyclohexane is an industrially important molecule mainly used for the production of epsilon caprolactum and adipic acid which are precursors to Nylon. Cyclohexane has a molecular formula C 6 H 12 and has a cyclic structure. At room temperature it exists as a liquid with boiling point 80.74 o C. Generally, representation of cyclohexane in a line structure form is shown as a hexagon but practically it is not the case. Cyclohexane has six C-C bonds and due to cyclic structure there is a restricted bond rotation. Rotations of bonds lead to the various conformations. The most important conformations of cyclohexane are enlisted below. Conformations of Cyclohexane 1. Boat 2. Chair 3. Twist boat 4. Twist Chair Boat Conformation In a boat conformation, four carbon atoms lie in a plane while remaining two carbons atoms (C1 and C4) are out of plane (above or below) but ...