Reaction of tropone with quadricyclene. An example of [π6 +σ2 +π2] cycloaddition

Tetrahedron Lettore Ilo. 5, pp 395 - 3%

REACTION AN

OF

EXAMPLE

(Reooived

Research

in

Cycloaddition

OF

was shortly after

6r

demonstrated tropone

In6 +e2

Tanida

Laboratory,

WITH

QUADRICYCLENE.

]

+a2

CYCLOADDITION

and Tadahika

Shionogi

Printed in Great Br1w.n.

Preee.

8 Co.,

Tsushima

Ltd.,

Fukushima-ku,

Osaka,

21 Deoombor1971; ruoeivodin UK for ~blioatlon

Jepcm

between

Pergmon

TROPONE

Hiroshi Shionogi

19%

and 4s addends by the reaction

reaction

between

u

between

a 6s system and a pair of stmined

(I,6

+,4]

of tropone

cycloaddition)

c bonds ([,6

1971)

predicted’

and

We have investigated

found the first example

+ c2 + a21

31 Deoe~ber

was theoretically

with cyclopentadiene.*

(2) and thereby

and quadricyclene

Japan

by the teninology

a

of cycloaddition of Woadward

and

Hoffmann’).

+

Equivalent mixture

amounts &L

consisting

by thin layer

mainly

and 2 were heated

of polymeric

chromatography

of crystals of another

yield.

the reaction

When

the other two products. agreement maxima

was traced

a cyclahepta-3,5-dienone

:

1

Ct4Hi40.

1 adduct

by vpc,

The elementary

with the formula

in cyclohexane

(Merck)

separated (4),

a 1

mp 52’,

the formation

analysis

: I

structure

was shown to be initially (70 eV m/e

at 1740 cm-l

and 279 (4800)

moiety2 but not a CH=CH.C=O

395

@,

gel followed

and a compound of unknown of?

adduct

on silica

in 9%

absorption

268 (4820),

of this mixture

mp 82.S-84’,

and mass spectrum

An ir carbonyl

at 221 mp (c 12900),

in the dark at 700 for 5 days to yield a ccmplex

Chrcmatogmphy

substances.

on KGFa

and a mixture

together

chromophore?

198 (M+))

yield; in 6%

predominant

over

of 2 were in

in CC14 and uv absorption

are compatible

with

the presence

The nmr spectrum of 2 in CDCIs

of

when 0.5 I,

amounts of Eu(DPM)3

1, H,3s), 6.86 and

9.09

derivatives.5

(t, 2, olefinic

(broad

gested by comparing

d, 2, J3,4 = 9,

of coupling

H3 and HB).

(six,

2, olefinic

of the six olefinic

between

(d,2,

of a plane

H, and H3 (or H,3 and Hp) and the presence of H3 and Hp hydrogens

tion of the carbonyl

whether

is 3 or2

H,3s was significantly difference,

shifts of H,3a and H,3s with varying larger

but that of2

(t-d,

2, H, and

is immediately

obtained

than that of H,3,, (Figure

-

to the norbornene

The molecular

H2, H,,

The between

ring.

by the difference

amounts of Eu(DPM)3. 1).

H,,,

of long range coupling

was determined

sug-

from norbornene

of symmetry in the molecule.

the endo orientations

the pseudo contact

derivative

(d-qui,4

H,),5.92

protons as three pairs and the six protons (H,,

of the presence

the structure

J3,,3a=I.7,H3and

data and references

H,30 and H2 (or H9) indicate group-

signals at 6 2.10

H3 and H&, 8.10

That 2 is a norbornene

these nmr data with the many available

The appeamnce

revealed

(m, 2, H, and y&4.63

H,, and H,3), 7.31

H3, and Hs) as three pairs is indicative absence

were added as a shift reagent

1.7,anti-H,3),4.26

J,3a,,3s=I0H~,J,3a,3=

(d-m, H,),

equivalent

Orientobetween

It was found that the shift of

model of 2 can rationalize

can not.

A

H 5

.

0

this

lo.

5

397

It was found that a compound identical

with

of 1 with a large excess of norbornadiene6’7 For4, l,J

uv max (cyclohexane)

Hz,

5.46

J3,4 = 8 Hz,

In general,

tion of a bicyclo(3.2.21 are consistent 9-one.

with

d, 1, H3,5.46-6.60 cycloaddition

nona-2,6-dien-4-one

this

[ 3.2.21

narbornene)

i,&

L

structure,

derivatives

but not with

of bicyclo[

exo) are distinguishable absence of long-range

the 13.2.2)

ring,

bridgehead

the structure

by the coupling

@

the clean AB quartet

However, ditions, period,

it was observed that2

that the yield and also,

into

norbornadiene

Addition reaction

Ht ,

absorption

with

either

H3, H7,

(q, 1, JdJ

the farma-

hepto-2,4-dien-

On the basis of these

(the C, and C6 protons the norbornene

Therefore,

in

bridgehead

Hz and H, must be

The endo,endo-6,7 --

ond exo,exo-6,7 --

on the carbonyl

side are defined

(substituents

= 11

and the uv max in 4

of a bicycloI4.2.11

protons

(d-m,

as

couplings

structure

tmnsformed

with

relative

H, and HI, respectively.

,6.

into norbornodiene

stage of reaction

the reaction

product from the reaction

that,

under the reaction

and increased

conditions.

con-

with

the reaction

Consequently,

it was con-

of _I_and 2, but wos formed after

conversion

of 2

.

of hydroquinone

as o radical

appears to be stereaselective,

reaction.

gradually

with

that 2 did not convert into &under

basis of these findings, present

7.01

1.15

between Ht and H7 (or H, and Hd and the presence or

of tl_was very minor at an initial

cluded that 3 was not a direct

and Ht,),

of _I_with 2. 6

(m, 5,

H6 and H, (or H7 and Hp),8 and it has been reported

is not consistent

by reaction

compound proceeds with

(l-h ond H7).

z and g are ruled out.

constants

between

coupling

to the endo H6 and H,, the exo H6 and H7 have much smaller Therefore,

Ht,,

The ir carbonyl

protons

nmr (CCIS

H2 and H8), 2.43-3.42

a 2n olefinic

no vicinal

nona-2,6-diene-done

coupling

1663 cm-t;

The H2 and H, bridgehead with

and structures

3.2.21

ir (Ccl&

moiety in 1 is suggested by the nmr data.

appear as a clean AB quartet,

endo to the norbornene

of ,I_ with

yield

as used for the reaction

(m, 4, Hte, Htt,

derivative.

and 2 are possible.

(Ht and HP) or with

360 (92);

(AB q, 2, J2,s = 9 Hz,

The presence of the norbornene

data, structures

protons

1.92-2.43

(d-splitting

H4).

under the above conditions

245 mu (sh, a 2150),

t2a,12s = 10 Hz, anti-H,*),

H,, and syn-Ht2),

the second odduct 1 is produced in 70%

scavenger has no significant

since the isomer5

we favor a concerted

It is of interest

endo side of the norbornene

ring;

cycloaddition

on the formation

was not found in the reaction

mixture.

mechanism and not a stepwise

to note that the newly-formed but the ethylene

effect

butadiene

bridge in ftresulting

bridge in3

of 2.

The

On the

mechanism far the

is located at the

from norbornadiene

is located at

No. 5

398

the exo side. REFERENCES 1.

2.

(a)

R. Hoffmonn

and R. Hoffmann,

Academic

Press,Inc.,pp

(0)

R. C.

Cookson,

S. Ito,Y. 3.

and R. B. Woodward,

Woodward

Fujise,

Refer to T. A.

4.

d-qui

5.

(o)

= doublet L. M.

Organic

Jockman

N.

K. Aona,

Y.

Vpc revealed

formation

An extensive

investigation

Abstracts 8.

(a)

H.

Sakon and Y.

T. Yono, Fujise,

minor 1

: 1 odduct, dr

Structural Ueyamo,

Tetmhedran

Letters,

Bull.

Chem.

six = sixtet,

N.Y

R. B.

GmbK

0

with

Organic

(b)

33,

1247 (1960);

whose structure norbornene

Organic

l9&,

775.

Sot.

Tetrahedron

Y.

Eu(DPM)a Pseudo contact

0.4 mol/Ligand shift induced

(1969); Letters

in

(b)

1966.

9;

405 (19By

was independently with the diene

Kitahara

Hiroshima,

Japan

Spectroscopy

wos not determined.

from the reaction

Chemistry,

Chem.

Resonance

230-231,288289

ond norbornadiene

with our determination:

Bull.

and so on.

Moss Resonance i,

Their mojor odduct

0.2

1.

1966,15;

Japan,

0.6 mol by Eu(DPM),

8

wos

and T. Uehom,

November,

in press (1972);

8

Fig.

(b)

1351 (1966). Sot.

Magnetic ., pp.

T. Tsuji, and H. Tanida, Hoyomizu,

4 in agreement

Commun.

Japan 39,

of Nuclear

and K.

and M.

Chem.

Sot.

Toyooka,

Press, New York,

and T. Uehoro.

of the 3rd Symposiucof

Tanido,

(1965); Chemie:

(1966).

Applications

of the reactions

ta hove the structure

Morrison, Chem.

of multiplets,

Muneyuki,

of another

Kitahoro

Bull.

&3,5026 --

d-m = doublet

Hota, R.

and A.

Nogose ond Y.

K. Sakoshito,

7.

reported

Inaue,

2nd ed, Pergamon

6.

out by Y.

Hudec,

Y.

and S. Sternhell,

Komezawo,

carried

T.

J.

Chem . Sot.,

of quintets,

Sot. 87,2046,4388

Chem.

(1970).

Drake,

1. Mukai, Amer.

Chemistry,

K. Tori, (c)

J.

Amer.

Verlag

T. Okudo,and

Nozae,

S. Kende,

83-85

B. V.

J.

The

1970, (b)

p. 38.

S. ItZ,

K.