Organic Nomenclature – The Basics

Organic Nomenclature Naming compounds that contain Carbon and Hydrogen Hydrocarbons: Contain only H and C

Alkanes Saturated Hydrocarbons (Max. # of H) Only single bonds CnH2n+2 for chains CnH2n for cyclic structures

Naming Unbranched Alkanes Determined by # of Carbons, end in -ane 1: meth- 5: pent- 9: non- 2: eth- 6: hex- 10: dec- 3: prop- 7: sept- 4: but- 8: oct C6H14 : Hexane C3H8 : Propane CH4 : ? C4H10 : ?

Branched Alkanes Alkyl Group: branch with ONLY H and C Methyl: 1 C: -CH3 Ethyl: 2 C: -CH2CH3 Propyl: 3 C: -CH2CH2CH3

Naming Alkanes Find longest C chain containing the most substituents, count C, write name Number C from closest substituent Name substituents in alpha order -More than one of each type use di-, tri- prefixes Indicate positions of substiuents Add commas between #s and hyphens between # & letter

Alkenes (pg. 79) Hydrocarbons with at least 1 double bond CnH2n Unsaturated Carbons Prefixes are same as alkanes, ending –ene C2H4 : ethene C4H8 : butene

Alkynes Hydrocarbons with at least 1 triple bond CnH2n-2 Unsaturated Carbons Prefixes are same as alkanes, ending –yne C3H4 : propyne C4H6 : butyne

Naming Alkenes & Alkynes Follow Alkane Rules Looking for longest chain that contains double bond (-ene) or triple (–yne) Multiple double or triple bonds add prefix (di-, tri-) and location before ending Ex: Prop-1,2-diene or 1,2-propdiene