6.1 Description and Properties

LEARNING GOALS

After   Chapter 6.1,    you will    be  able    to:

Recall  the suffixes    used    in  aldehyde    and ketone  nomenclature

Describe    the reactivity  of  the carbonyl    carbon

Recognize   common  reactions   used    to  form    aldehydes   and ketones

Predict the boiling point   of  a   compound    based   on  its oxidation   level

A ketone has two alkyl groups bonded to the carbonyl, whereas an aldehyde has one alkyl group
and one hydrogen. This means that the carbonyl in a ketone is never a terminal group, whereas it
always is in an aldehyde. Like many organic compounds, aldehydes and ketones are often strong-
smelling compounds. Volatile carbonyls are found in many spices, including cinnamon
(cinnamaldehyde), vanilla (vanillin), cumin (cuminaldehyde), dill (carvenone), and ginger
(zingerone).

KEY CONCEPT

An  aldehyde    is  a   terminal    functional  group.  A   ketone, on  the other   hand,   will    always  be

internal    and can never   be  a   terminal    functional  group.

NOMENCLATURE

Aldehydes are named by replacing the –e at the end of the alkane name with the suffix –al. Common
names for the first five aldehydes, shown in Figure 6.1, are formaldehyde, acetaldehyde,