Baeyer ring-strain theory

Woker attempts to apply this strain theory to ring compounds, and considers that the five carbon atom ring produces less strongly odoured substances than any other and points out that, according to Baeyer s strain theory, the five carbon ring has the least internal tension. It is very doubtful if this contention is correct, since the penta-methylenes do not seem to be less strongly odoured than other polymethylene ring compounds. ... 

It will be seen that whereas iodine leads to 1 2 tetra- and di-basie esters, methylene, ethylene, etc., iodides yield respectively 1 3, 1 4, etc., esters. The yields in these ring syntheses, as in most others, vary in agreement with Baeyer s Strain Theory. ... 

Structure X in Figure 300 shows interpenetrating tetrahedra with carbon centers and a single bond between these carbons. Van t Hoff correctly postulated that there is free rotation about such single bonds. Structures XIa, Xlb, XII, and XIII rationalize cis and Irons isomerism (e.g., the difference between maleic acid and fumaric acid). Structure XIV explains the widespread occurrence of six-membered rings in chemistry and aspects of Baeyer s strain theory. ... 

Baeyer s strain theory applies to rings with atoms in a single plane. It is not necessary for the atoms to be in a single plane, and all sorts of odd rings can be (and are) formed in which this restriction does not hold. 

The Baeyer strain theory is useful to us in identifying angle strain as a destabilizing effect. Its fundfflnental flaw is its assumption that the rings of cycloalkanes are planar-. With the exception of cyclopropane, cycloalkanes are nonplanar. Sections 3.5-3.13 describe the shapes of cycloalkanes. We ll begin with cyclopropane. 

Baeyer strain theory (Section 3.4) Incorrect nineteenth-century theory that considered the rings of cycloalkanes to be planar and assessed their stabilities according to how much the angles of a corresponding regular polygon deviated from the tetrahedral value of 109.5°. 

While correlating the stability of the ring with their size Adolf von Baeyer advanced in 1885 his famous strain theory. We know that the four valencies of a carbon atom go to the four comers... 

Baeyer strain theory org chem The theory that the relative stability of penta- and hexamethylene ring compounds is caused by a propitious bond angle between carbons and a lack of bond strain. ba-or stran, the-3-re baking soda See sodium bicarbonate. bak-ir, sod-s ... 

It is of historical interest to note that the Baeyer strain theory with its planar rings predicts only one form of decalin with the ring-junction hydrogens on the same side of the molecule (Figure 12-23). The Sachse-Mohr concept of puckered strain-free rings allows for two isomers. In fact, Mohr predicted that the two isomers of decalin should exist before W. Hiickel (1925) succeeded in preparing them. Both isomers occur in petroleum. 

Perhaps it is appropriate that this review be written some 100 years after the report of the first syntheses of cyclopropane derivatives by von Baeyer and Perkin and the formulation of the theory of ring strain by von Baeyer. The chemistry of small ring compounds has risen to prominence in the last 30 years. The popularity especially of the three-membered rings as intermediates in synthetic transformations has been due primarily to their latent energy content and to the almost endless number of chemical transformations in which these compounds and their derivatives can participate. New applications and novel permutations of the basic systems continue to appear at a fast pace. The fascinating chemistry... 

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