aldehydes

1. ALDEHYDES, KETONES AND CARBOXYLIC ACIDS
NOMENCLATURE OF ALDEHYDES AND KETONES
the word aldehyde signifies a product obtained by dehydrogenation of alcohols. in the latest
IUPACsystem aldehydes are named as alkanals .
1. Common system
the commom names for aldehydes are derived from the carboxylic acids they are obtained .the
suffix 'ic acid ' in the commom name of the acid is replaced with the ending
aldehyde.Thus CCH3CHO, which on oxidation giveds acetic acid is called acetaldehyde.
branching if any in the aldehyde chain is indicated by the greek letters alha,beta,gamma and delta.
the carbon atom directly attatched to the CH=O group is called alpha carbon.
2.IUPAC system
*Select the longest carbon chain containin g the _CHO group
* Nu mber thec atoms in the longest chain assigning numer one to the aldehydic carbon.the CHO
group is always present at one end of the carbon chain.. Thus , the
position one of the aldehydic group is generally not shown in the
iupac name
*replace the correspondinf ‘e’ of the corresponding alkane by’al’