Carbonyl group C = O Aldehydes Ketones Carboxylic acids Esters
In an aldehyde, at least one H atom is attached to a carbonyl group. In a ketone, two carbon groups are attached to a carbonyl group. Aldehydes and Ketones C = O
Step 1- Identify the root Select the longest carbon chain that contains the carbonyl group (C=O). Name the parent alkane. Drop the –e on the parent alkane to get the root. Step 2- Identify the suffix For aldehydes, the suffix is –al carbonyl group C=O is always C1, do not include the number in its name. Step 4- Name the compound Combine the prefix, root, and suffix to name the compound Naming Aldehydes Step 3- Identify the prefix Number from the end nearest C=O group. Name and give the position of any alkyl side groups as you for a hydrocarbon.
Common names for the first two aldehydes use the prefixes “form” (1C) and “acet” (2C) followed by “aldehyde”. O O O ║ ║ ║ H─C─H CH 3 ─ C ─HCH 3 ─CH 2 ─ C ─H methanal ethanal propanal (formaldehyde) (acetaldehyde) Naming Aldehydes
Name the following aldehydes Root: hexan- Suffix: -al Prefix: 4-methyl Name: 4-methylhexanal
Name the following aldehyde Root: decan Suffix: -al Prefix: 3-ethyl-6-methyl Name:3-ethyl-6-methyldecanal
Draw 5-ethyl-4-methyloctanal Root: eight carbons Suffix: aldehyde Prefix: methyl on C4, ethyl on C5
Step 1- Identify the root Select the longest carbon chain that contains the carbonyl group (C=O). Name the parent alkane. Drop the –e on the parent alkane to get the root. Step 2- Identify the suffix Start numbering at the end nearest the carbonyl group. Determine number for carbonyl carbon. Suffix contains number for carbonyl carbon and -one Step 4- Name the compound Combine the prefix, root, and suffix to name the compound Naming Ketones Step 3- Identify the prefix Name and give the position of any alkyl side groups as you for a hydrocarbon.
Name the following ketone Root: hexan Suffix:-2-one Prefix:3,3-dimethyl Name: 3,3-dimethylhexan-2-one
Draw the structural formula for 5,5-dimethylheptan-3-one Root: seven carbons Suffix: carbonyl on C3 Prefix: two methyls on C5
Physical properties of Aldehydes and Ketones 1.They have strong odors (ketones have pleasant odors). 2.They are polar compounds. 3.Only dipole-dipole interactions (no hydrogen bonding). 4.Low boiling points compare to amines and alcohols. 5.Soluble in water (not soluble in nonpolar compounds). δ+ δ- δ+ δ- H O H δ+ Hydrogen bond with water. Higher than hydrocarbons. C-O3.5-2.5 = 1
Chemical properties of Aldehydes and Ketones 1. Oxidation: only for aldehydes (not for ketones). K 2 Cr 2 O 7 H 2 SO 4 CH 3 ─CH 2 ─CH 2 ─CH 2 ─C─OH = O CH 3 ─CH 2 ─CH 2 ─CH 2 ─C─H = O Pentanal Pentanoic acid K 2 Cr 2 O 7 : Oxidizing agent