NMR spectra of some secondary substituted adamantanes part I. 2-Mono-substituted adamantanes

PP. Jp2_5-39!2S,1967.

Tetrahedron Letters NO&,

NMR

SPECTRA

OF

PART

SOME

SECONDARY

SUBSTITUTED

2-MONO-SUBSTITUTED

I.

F.W. Philips-Duphar

Pergamen Press Ltd.

van

Deursen

Research

Printed in Great Britain.

ADAMANTANES

ADAMANTANES

P.K. Korver

and

Laboratories,

Weesp,

the

Netherlands

(Received in UK 9 July 1967)

The

NMR

spectra

cussed

by

In

the

present

of

some

article

P. von we

want

nine

Schleyer

to discuss

adamantanes,

different

kinds

adamantanes

these

protons

are

to be

1.

J(gem)

=

2.

J(vic)

= 2.6

expected 11

ary J(long

R.

adamantanes

have

been

extensively

dis-

and

substituent

shifts

(1). the

which

NMR

spectra

have

lower

symmetry

than

l-mono-

adamantanes.

substituted

3.

and

substituted

2-mono-substituted

are

Between

tertiary

Fort

F.C.

substituted

There

of

range)

-

of

(Fig. the

protons

in

P-mono-

1).

following

coupling

constants

: 13

Hz,

Ha,

in

as

all

substituted =

1 Hz,

a W-arrangement

in

cyclohexanes

cases

equal,

adamantanes coupling

over

(3).

3923

(2). as

in

terti-

(1). four

I 1’ bonds

in

FIGURE

1

No.40

3924

All

possible

spin

interactions

are

given

in Table

TABLE Possible

proton

vicinal BE'

CC'

D

(D')

BH

(B~H)

EI'

DD'

C

(C')

BH

(B'H)

A (A)

EE'

F

(F')

BG

(BIG)

CI'

FF'

E

(E')

BG

(BIG)

BB'G

II'

GH

E'C'

(GH)

in brackets column marked

we

selected

2-hydroxy-,

virtual

(4)

region

which

proton

A,

In all

spectra

confirmed on

vicinal

by

(al.5

an

"AB"

comparison

than

the

because

substituent

are

more

Only

in

case

with

J =

protons

the

12 Hz

the

of

in

"AB" F.

a

from

deshielded

the

are

2-chloro-,

given

not

appear

detectable.

exception

of

2-bromo-

in Fig.

absorptions

at

is

the

observed.

60 MHz

system

Then

the

protons

and

must

2, as

All

and

a - e. broad

signals

signal

This

by

appear

produced

position

"AB"

system

spin-tickling.

belong

down-field

1,3-diaxial

2-hydroxyadamantane

arising

are

the

spectra

E and

protons strongly

all

J = 12 Hz

this

protons

C,

the

with

MHz

the

by

identification.

with

differences, to

with

of

Z-amino-,

100

constants

its

system

at

coupling,

- 62.5).

facilitates

chemical-shift

D rather

coupling

(EC)

couple with protons with a prime.

and

same

(C'I)

BB'H

Due

the

(E’I)

CC'DD'II'

measured

in

(GH)

EE'FF'II'

spectra

in which

GH

H

The

bands

DD' (AC~D~E~F~)

G

investigation

long-range

range

ACDEF

2-iodoadamantane. to

long

BB'

first

this

a)

Interactions

A

a) Protons

For

I

Spin-Spin

geminal

I.

to part

with

Based

the

protons

must

arise

respect

is

to

C and from the

(5). is

the

E and

other F.

"AB"

system

observable,

No.40

FIG.

2a

2-Chloroadamantane

FIG.

2b

2-Bromoadamantane

FIG.

2c

2-Iodoadamantane

a)

a)

a)

ab)

FIG.

2d

2-Hydroxyadamantane

FIG.

2e

P-Aminoadamantane

ab)

FIG.

3

P-Bromoadamantane

a)

PROTON

A IRRADIATED PROTONS 6 yH2/2n=lOHI

..A.

A a) b)

Measured as ae internal OH

and

NH2

5% solutions standard. protons

removed

in deuterochloroform by

deuteration.

on

J

y

‘

4.7

a Varian

IRRADIATED PROTONS 0 yli2/2n=u Hz

NORMAL

4.6

HA

100

with

TYS

3926

No.40

In the ence

other

cases

between

cal

shift

The

signal

where

protons

of

this

from

the

A the

signals

proton

B the

signal

ton

D the

In

the

two

signal

spectra

protons

tons

protons

G and

actions.

It

hidden of

hidden

Chemical

the

the

on

band

found

and

under

and

the

signals

and

of E and

('

D

B

NH2

2.98

1.8

OH

3.75

l.H!> 2.06

Cl

4.39

2.05

2.27

I’.57

Br

4.68

2.13

-3.33

I

5.00

2.16

E

that the

the

protons

absorptions

By

irradiating

hand

many

F,

the

pro-

of more

band

band

E,

irradiating

of

of

two

the

pro-

residual

vicinal

and

than

spin

inter-

of G and 1.

protons

In

the

I, G,

H are case

and

H

F.

shifts

are

given

in Table

II.

II

Shifts

in

2-Substituted

CH

Adamantanes

substituent I

B

C

D

a)

shift E

I

(F) 0.02

1.8

1.7

0.20

-0.22

1.7

0.04

0.31

-0.22

1.86

1.8

1.76

0.20

0.52

-0.18

0.11

0.01

1.62

1.91

1.9

1.78

0.28

0.58

-0.13

0.16

0.02

1.71

1.95

1.9

1.79

0.31

0.63

-0.04

0.20

0.04

1.53

a) A negative sign means an dary and tertiary protons

1.77

By- irradiating

absorptions

of

l‘rom TMS) (F‘)

the

F.

1.8

I.'15 I.53

2.38

their

substituent

Substituent

A

of

the

chemi ca 1 311i I‘t ( ppm

subst.

because

from

tllr corresponding

Shifts

as

chemi-

Hz.

absorption

I,

dif'ier-

the

E and

By

sharp

protons

integration

3).

J = 2.6

the

of

slightly-.

a relatively of

Therefore

resonance.

(Fig.

with

frequency

shift

double

singulet

the

8 Hz.

D sharpened

side

TABLE Chemical

by

triplet,

broader

accurate

signals

chemical

up-field

2-aminoadamantane the

mean

derivatives

much

the

the

B and

to

observed,

about

identified

a sharp

is

than

a sharper

belongs

between

and

shifts

by

band

less

only

protons

the

be

be

B was

halogen

H should

2-hydroxy-

are

protons

present

is

under

furnishes

of

strong

F must

of A became

This

F.

one

of A became

of

is

E and

E and

band

proton

only

1.82

1.60

0.07

-0.06

For the chemical shifts for up-field shift. in adamantane b1.75 and 61.85 are used.

secon-

NO.40

3927

Relatively

little

cyclohexane groups The

The

in

chairs,

substituted

trend

(Table

is known

and

in

values

about

substituent

contrast

to

cyclohexane of

the

shifts

substituent chairs

(e.g.

substituent

shift

of

ring-bound

shifts

of protons

methyl

groups

of

the

protons of methyl

in

protons

in

steroids

D are

(6)).

remarkable

II).

1,3-diaxial

smaller

than

deshielding the

deshielding

The

vicinal

substituent

ues

as

the

opposite

substituent

The

trend

the

compared

of

substituted

with

of

to

by

shift

OH

the

has

shift

the

in

trend

the

but

OH-group

has

been

appears steroids

gives

in

is

A

by

(Table

III).

lower

curious

val-

fact

is

steroids.

opposite

explanation given

to be

somewhat

III).

found

shift

A possible

adamantanes

in

(Table

substituent III).

adamantanes

substituents

same

to

l,J-di-equatorial

l-substituted

Cl

adamantanes

due

(Table

and

same

l-substituted

adamantanes

behaviour

due

of Fort

for this

and

l- and

2-

unexpected

von

R.

Schleyer

(1).

TABLE Comparison

1,3-diaxial

of

III

Substituent

Shifts

1,3-di-equatorial

a)

1

vicinal

I

subst.

Ad

;rb) steroids(4)

OH

0.31

0.45

Cl

0.52

0.63

Ad

2

b)

Ad

I')(')

Ad

2 b,

Ad

l')(l) steroids

d)(4)

Br I A negative sign means an up-field b) Ad 2 = 2-substituted adamantanes. c) Ad 1 = l-substituted adamantanes. d) Shift of an equatorial proton due

In a following in

relation

paper to

the

we

shall

discuss

stereochemical

shift.

to an

the

axial

substituent.

substituent

configuration

of

shifts

in more

2,4_disubstituted

detail

and

adamantanes.

3928

NO.40

ACKNOWLEDGEMENT

The

authors

the

samples,

N.V. for

are

Philips his

indebted J.

to Dr.

Eindhoven

continuous

to Dr. Bakker for

J.L.M.A.

and

NMR

H.M.

Schlatmann v.d.

and

Bogaert,

measurements

at

H.W.

Research

Geluk

for

supplying

Laboratories,

~OMJYIZ,and

to Dr.

789

(1965).

K.J.

Keuning

interest.

REFERENCES 1.

R.C.

2.

Jean-Claude

3.

A.

4.

J.I.

Musher

and

E.S.

5.

N.S.

Bhacca

and

D.H.

Fort

Rassat,

and

R.F.

van

Muller, C.W.

Chemistry, 6.

P.

Ziircher,

R.

Schleyer,

Bul.Soc.Chim.Fr., J.M.

Jefford,

p.

Corey,

Lehn

and

2027

i+,

!g,

Inc., 2054

(F864).

B. Waegell,

Applications

Holden-Day

Helv.Chim.Acta

p.

Tetrahedron

Williams, 185,

20, --

J.Org.Chem.

791

Tetr.Let.,

(1963).

233

(1964).

(1962).

of NMR 1964.

p.

spectroscopy

in

Organic