Aldehyde ,ketone preparation (Part - 7)- Aldehydes, Ketones and Carboxylic Acids, Chemistry Video Lecture - Class 12 | Best Video for Class 12

hello friends this video on aldehydes
ketones and carboxylic acid part seven
is brought to you by exam viacom normal
for you now let's understand some of the
method of preparation of early hydrate
ketones what we have done till nine we
have learned what is early hide in
ketone and also we have learned how to
write the structures of Rd and ketones
how the name early my pinky toes there's
common name is I person in now I'm
studying some of the methods to prepare
early Henry told the way I have bucketed
in this whole chapter is early and it on
is one part and carboxylic acids one
part because I Lehane we don't have lot
of similarity we talked about the
chemical property physical property or
method of operations they have similar
properties it so for allocating ketone
we can prepare by oxidation of alcohol
dehydration of alcohol hosana license of
al we can also prepare from outlines we
can also prepare by heating calcium
salts of carboxylic acids and we can
also prepare from the Kliq knowledge in
fact there other wastes also to prepare
aldehydes and ketones but we'll focus
only on these four aldehydes and ketones
we will study separately some methods
which are used specifically for early
height and some for Kito's but these
methods which I am discussing these six
methods which I am discussing now is for
both aldehydes and ketones with these
six methods you can prepare both
aldehydes and ketones and let me deeply
this is my only height this is my
carbonyl group
the H is my aldehyde carbonyl group with
two R is mine and this is how it looks
actually if you see this is the 3d view
of aldehyde and keto if you see this is
all in one plane this carb awesome you
have discussed is carboxylic group is
all one plane in all in one plane so let
us discuss the first method that is
oxidation of alcohol so it is oxidized
by
estephe ID k2cr2o7 that is potassium
dichromate
k2cr2o7 so strong oxidizing agent you
can oxidize so if you take one degree
alcohol you get aldehyde
all right here first one degree alcohol
and you oxidize the same reagent and
NASA dick and that's like maybe MH plus
you get aldehyde and if you take two
degree alcohol and you mean oxidize this
you get keyed on it like will T there
are so many oxidizing is in the market
for example chromic acid from it's all
dichromate Saul permanganate PCC is PI
radium chlorochromate and PDC is
palladium dichromate there so many
oxidizing agents you can use k2cr2o7 the
most common you can use any organizing
agents oils take you to this example for
the alcohol for example I have this
alcohol ch3 ch2 now if I oxidize this in
presence of my oxidizing agent in this
cell lakitu cr2 o7 in H+ may be sulfuric
acid what I get is ch3cooh this is what
you get but the second the ketone this
part you can show you if I take let's
suppose 2 degree alcohol something like
this o H and I oxidize this if you see
this is a two degree alcohol this carbon
is the hero cop attached to two other
carbons
today the alcohol or you oxidize this
you get ch3 C this becomes double bond o
c2h5 if we see this becomes ketone right
this is butane arm
right for carbon we turn on and this is
eath null this aldehyde this ketone if
you see that's why if you took if I took
one degree alcohol I got aldehyde if I
take two degree you're calling it kita
right hope you'll remember this one
degree alcohol aldehyde two degree
alcohol ketone it should be if you take
three degree alcohol you won't need
anything because there has to be a
hydrogen to be removed here right if we
take 3d or you'll not do anything so it
has to be one lady or two degree so you
take one area called oxidize it take it
aldehyde it a 3d alga oxidize it you get
ketone the next is dehydrogenation of
alcohol the reaction looks similar to my
oxidation of alcohol here also same
similar stuff if I have one degree
alcohol and if I do a dehydrogenation
that is you remove hydrogen's with
aldehydes and if you have two degree
alcohol remove hydrogen there is
dehydrogenation you get ketones 3db
alcohol will not work here so here what
we do is we take alcohol in this case we
take in this case I will take one degree
alcohol and then what I will do is since
it is one degree alcohol it will have
hydrogen alpha hydrogen I'll heat this
with a heated copper or silver at a very
high temperature may be 580 Kelvin and
you will get the alcohol and hydrogen
back example the common equation for
this is you have our ch2oh this means
this implies this is a
one degree alcohol and you have this cop
over a tub I wit Kelvin you get our Co H
and hydrogen is out if you see this
hydrogen this hydrogen is clicked off
call the hydro generation wand reaction
I have CH 3 CH 2 O H when it reacts with
copper at IVD Kelvin and gives ch3cooh n
so you see one hydrogen from here one
Idol from here is kicked out and you get
this aldehyde let's see the same
reaction for now
ketones to DV alcohol again the same you
heat at 580 Kelvin so if you see the
reaction is I have our I have CH we now
have our and then I voyage in this case
if you see this is a two degree alcohol
you again hero's you heat with copper
atoms 580 Kelvin and high 73 to be
specific you get our Co it can be our -
just to you with specific a general
equation once the hydrogen is emitted so
here also this - hydrogen comes out
right our typical example can be I have
CH 3 CH o H I have CH 3 here I can take
anything else also here will be cs3 same
PI 7 3 Kelvin this is exact but they can
take any of this temperature it won't
make much difference here and hydrogen
gases kicked out
so you can do any of these either you
can use this copper and do a
dehydrogenation or you can use oxidizing
agent to convert alcohol aldehydes and
ketones right any of these methods can
be used to convert alcohols to already
hides and Cheetos
the next is ozone lysis of alkenes
please note here we do personalizes of
alkenes not even alkanes alkenes so here
my alkenes are oxy de Occidente
to form ozone I'd and that it is then
reduced it is introduced by hydrogen or
zinc or acetic acid this only ways to
reduce it to form either aldehydes or
ketones or terms now whether it will
form aldehydes or ketones that depends
on the number of alpha hydrogen's so if
it has two alpha hydrogen it becomes
aldehydes if it has zero or one alpha
hydrogen it becomes ki dance I'll show
some examples for this but first let's
see the reaction mechanisms example I
have our C H double bond or C or - hey
let's suppose I have this compound on
this first I'll use ozone correct so you
know react with ozone in presence of CCL
4 what happens oh and if you see is
something like this right so one part
has plus charge when patas negative
charge
the one which has negative charge will
have 603 lone pair of electron this will
have four and this will also have four
Nordahl happiness this is a double bond
it has lot of electrons this guy this
double bond will attack on this oxygen
the positive charge and the one with the
no since this will bond will break this
carbon will get like positive charge
this negatively charged oxygen attack
this card correct so with this what you
get is what I am done is on this I'm at
act ozone o3 so what this you get is RC
and this double bond will break and you
get R dash here and then you get
something like this correct and it is
called ozonide now on this in fact this
will tautomerize
tautomerize this totem arise to form
ozone I'd this is not was a night sorry
II thought Amara is to form asana Indian
oxygen will come here
the rearranged answer
yeah this is my ozonide please buy one
right correct
so I have got my buzz right now on this
what I will do is I'll reduce it with
hydrogen or Jing this what you get is
this becomes our C double bond o H & R -
see this if you see eight whatever this
becomes double bond and / H this becomes
double bond in a way this goes off
correct it also gets water is odd to see
we see here it had two alpha hydrogen's
this and this see it has two hydrogen
the output I goddess aldehyde itself I
got only aldehyde at output alright so
for a difference in area where I have
one or zero alpha hydrogen in that case
I'll get children also so if I have one
alpha hydrogen then I will get ketone
and aldehyde so sure the snail you for
example I have ch3 ch2 one see here I
have ch3 and a half ch3 and I do over
the lysis of this so optimisation what
will happen and I get something like
this
correct and now if I do a reduction what
will happen is I will get this compound
let me draw it this one ch3cooh right
Plus this compound cs3 Co cs3 all right
this is my aldehyde this is my ketone
correct so the only thing is if you have
a hydrogen here it becomes already hide
if you have al-qaeda here it becomes
keto say both the hydrogen you get both
aldehydes if one is hydrogen what is
alpha L you get one aldehyde or ketone
then both are alpha then you get both as
ketone correct if you instead of s you
put some are this becomes our here
becomes the ketone so that is the logic
if you want to get draw a case where I
have zero alpha hydrogen this case I can
draw so here I will show you that this e
to H Phi via we get both as ketones so
with this what do you get is correct
this is what you get now on this if you
add the reduction what you get is ch3
this is one come from this particular
part and the other is this guy and some
hydrogen guess what right this is the
output if you see both are ketones it
all depends on the number of one per
hydrogen if you have zero alpha hydrogen
you get both ketones 101 ketone world an
aldehyde two alpha hydrogen butas are
they correct this is the method of
aldehydes and ketones reputation by
hozier lysis of alkenes thank you visit
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