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Chapter 12 Alkanes. 12.5 Cycloalkanes. Cycloalkanes. Cycloalkanes: Are rings of carbons that can be drawn as geometric figures. Have a general formula of C n H 2n or 2 H less than the alkane. propane C 3 H 8 cyclopropane C 3 H 6 .
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Chapter 12 Alkanes 12.5 Cycloalkanes
Cycloalkanes Cycloalkanes: • Are rings of carbons that can be drawn as geometric figures. • Have a general formula of CnH2n or 2 H less than the alkane. propane C3H8 cyclopropane C3H6. butane C4H10 cyclobutane C4H8. • Are named with the prefix cyclo- in front of the corresponding alkane name.
Naming Cycloalkanes A cycloalkane with: • One substitutuent is named by placing the name of the substituent in front of the cycloalkane name. • Two or more substitutuents is named by numbering the ring in the direction that gives the lower numbers to the substituents.
Constitutional Isomers • The rigid ring in a cyclic structure prevents rotation of substitutuents bonded to the ring. • A cyclic structure with two substituents has two isomers called cis-trans isomers. • The cis isomer, has two substituentson the same side of the ring. • The trans isomer, has two substituentson opposite sides of the ring.
Cis-Trans Isomers • The compound 1,2-dichlorocyclopropane has cis-trans isomers. Cl atoms on Cl atoms on same side opposite sides