Ring compounds strain

The polarization fiinctions are essential in strained ring compounds because they provide the angular flexibility needed to direct the electron density mto the regions between the bonded atoms. 

The Ratnberg-Backlund reaction has been used for the preparation of strained unsaturated ring compounds that are difficult to obtain by other methods. A recent example is the synthesis of ene-diyne 5" that has been used as starting material for a Bergman cyclization ... 

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. ... 

Surprisingly enough, the effect of ring strain on the electronic structure of the —SO and —S02 groups is rather small. Sulphur charges and S—O BOPs are almost constant in the ring compounds and in the dimethyl derivatives. The only exception is a substantially weaker C—S bond (lower BOP) in ethylene episulphoxide. 

TABLE 4.5 Some Strained Small-Ring Compounds... 

The strained-ring compound 1,1-dimethyl-l-silacyclobutane (which may be regarded as an olefin of organosilicon chemistry) reacts with diiron nonacarbonyl in benzene at 6°-20°C as shown in Eq. (100) (89). (There is here some analogy with the reactions of transition metal complexes with strained hydrocarbons, which often produce valence tautomerization.) The... 

Small ring compounds represent a fair portion of strained organic systems in which the geometry of sp and that of sp carbons have been distorted from the ideal configurations. Foremost among these reactive molecules are the small ring heterocycles, such as thiirane and thiirene oxides and dioxides. ... 

See Other C-NITRO COMPOUNDS, STRAINED-RING COMPOUNDS... 

See other endothermic compounds, strained-ring compounds... 

Cyanocyclopropane (Cyclopropanecarbonitrile) [5500-21-0] v i CN Preparative hazard See 4-Chlorobutyronitrile Sodium hydroxide See other cyano compounds, strained-ring compounds c4h5n... 

See Other DIOXETANES, STRAINED-RING COMPOUNDS CYCLIC PEROXIDES... 

See Other STRAINED-RING COMPOUNDS 1918. Vinyl propionate... 

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