β-Lactone as intermediate in the perkin reaction catalyzed by tertiary amines

Tetrahedron Letters,Vo1.23,No.36,pp PrInted In Great Brltaln

P-LACTONE

0040-4039/363723-02$03.00/O 01982 Pergamon Press Ltd.

3723-3724,1982

AS INTERMEDIATE CATALYZED

IN THE PERKIN

BY TERTIARY

REACTION

AMINES

Stefan Klnastowskl and Anton1 Nowacki Institute of Physics and Chemistry, Academy of Agriculture, 60-625 Poznafi, Poland Wolska Polskleqo 75, Abstract:

The Perkln

according

to the aldol-type

mechanism

in which

yielding

Recently

proposed

we reported

with

action

between

suggested

latter

was

that

further

paper

and acetic

a progressive implied

the reaction

species

studled

that

of ketene,

We

and amine,

clnnamlc

earlier

reaction

as catalyst'.

anhydrlde

acid.

by Hurd

lntermedlate2.

In the presence

the band was taken

The re-

and Wllllams

However,

the

due to an unstable

between

the proportions

1:15-30

solvent

temperature

at room

a progressive

was

reactlonl.

nately

too

(The

1, acetic

performed. over

the

between

this

band

ketene

at 1830 cm

product.

The NMR spectrum

the intensity

of the band

of 2. Thus

was proved,

and I showed -1 . This of

at

the hypothesis

and supported

further

by

acid as the final product.

increase

demonstrating

Perkln

of a

and demonstrate

reaction

prepared

the presence

and Wllllams

of the formation

ketene,

of trlethylamlne.

of absorption

confirmed

by Hurd

with

between

at the time when

of p-nltroclnnamic

the reaction

conflrmatlon

in the Perkln

of the reaction

and then decay

mlxture3,

presented

was observed

spectroscopic

1s formed

anhydride studies

increase

the formation

reaction,

in the Perkln

product,

of p-nltrobenzaldehyde

1830 cm-l was at the maximum,

Next,

to the

acid.

trlethylamlne

via a R-lactone

we provide

that the same

previously

was

to run not

and cycloaddltlon

of acetic

the Perkln

and bezaldehyde

it proceeded

IR Spectroscopy

fact

by reaction

to afford

in the reaction

aldehyde

of ketene uslnq

is found

but according

to the unsaturated

anhydrlde

generated

amlnes

not proved.

In present O-lactone

mechanism

the intermediacy

benzaldehyde ketene

by tertiary

is the formation

cleaves

and acetic

that ketene,

reacts

stage

which

benzaldehyde

catalyzed

condensation

the first

a a-lactone,

between

who

reaction

anhydride

several

intermediacy

low ior it to be detected

The subsequent

experiment

showed

and trlethylamlne

decomposes

at room

proceeded

days. Aqaln,

and then decay

concentration

and trlethylamlne

The reaction

In the course

of absorption

of 2 under

of 2 under

these

mixed

in

in the absence

band

at 1830 cm

the condltlons condltlons

of

of this -1

of the

was unfortu-

by NMR spectroscopy). that prepared temperature 3723

1 mlxed

with

acetic

to p-nltroclnnamlc

anhydrlde

acid after

3724

several

days

leading anion.

. Moreover

mainly

of minor

observation

It was

found

to p-nltroclnnamlc

On the other

a series

yield

5

nand,

acid,

amine was

products

that decomposltlon

rather

is catalyzed

found

of 2 In dloxane,

exclusively

to catalyze

than the acid, which

that the use of excess

amine

by the acetate

the decomposltlon 1s consistent

in the Perkln

synthesis

of 2 to

with

the

diminishes

the

of the reaction.

The observations

presented

above

encourage

us to propose

the following

mechanism:

(CH3C0)20

+

NEt3-

CH3COAEt3

0 II p-NO*-C6H4-CH

+

CH3COG

c=o +

*

(2)

-

The confirmation support

Acknowledgment:

p-N02-C6H4-CH=CH-COOH

of the fact that for the ketene This

research

of Sciences,

References

+

CHjCOz

?--Y=O p-N02-C6H4-CH-CH2

$H2 -

(1,

additional

CH2=C=0

-

the reaction

goes

through

2 provides

mechanism. was

MR.

supported

by the Polish

Academy

I. 12. 1. 1.

and Notes

1) S. Kinastowski

and H. Kasprzyk,

Bull.

Acad.

Polon.

Sci. Ser.

Chum.,

26,

907,

(1978). 2) Ch. D. Hurd

and J.W. Williams,

3) IR (C~Cl~).~~~=i830 4.05(dd,

lH, Jgem=16

J

=5.5 Hz), trans consistent with

D.M. Grant, 4) The samples amine

band

of reaction

3l,

mixture

completely

After

(Received

3001,

(1883).

in UK 5 July

5.62(dd,

protons).

1982)

962, (1936).

lH, J

=16 Hz, J ...=4.5 gem lH, Jcls=4.5 HZ,

The data presented

available:

H.S. Gutowsky,

were

analyzed

after

removal

out p-nltroclnnamlc

one day at room

temperature

acid was

was prepared

of excessive

acid

produced.

the 1830 cm

-1

formed.

as described

Hz)

are entirely

H. Karplus,

1278, (1958).

and p-nltroclnnamlc

5) a-(p-nltrophenyl)-8-proplolactone Ber., l6,

data

and after washing

used as solwent.

vanished

Hz),

4H, aromatic

Phys.,

Sot., 2,

(CDC13).63.4(dd,

Hz, Jtrans=5.5

7.9(m,

J. Chem.

J. Am. Chem.

'H-NMR

the literature

and anhydrlde

CHC13 was

cm-l;

by A. Basler,