Full text of DOI:10.1016/0031-9422(71)85040-9

1971, Vol.
pp. 1647 to 1651.
Press.
Printed in England.
DERIVATIVES OF NORDEHYDROABIETANE FROM
PINE BARK
J OHN W. ROWE and
A.
Forest Products Laboratory,? Forest Service, U.S. Department of Agriculture, Madison,
Wisconsin 53705, U.S.A.
and
A LBERT W. BURGSTAHLER and JON W.
Department of Chemistry, University of Kansas, Lawrence, Kansas 66044, U.S.A.
(Received 14 October 1970)
And
and
have been
by synthesis. Three
Dougl.).
isolated from jack pine
Lamb.) and their constitution
norabietatetraenes have been detected in western white pine
INTRODUCTION
IN THE course of our investigations of the nonpolar extractives of pine
we have
encountered several new derivatives of nordehydroabietane which evidently arise from an
oxidative free-radical decarboxylation of dehydroabietic acid analogous to that observed
with lead
Since woody plants synthesize lignin through a nonspecific
radical oxidation, these nordehydroabietanes may be true in vivo
RESULTS AND DISCUSSION
We initially isolated
Lamb.) bark and characterized it as the
from jack pine
Later we were able to make
direct spectral and GLC comparisons of the free alcohol with authentic samples of
prepared both by ourselves and by others. A new synthesis of was developed involving
lithium aluminum hydride (LAH) reduction of the
thus providing confirmatory proof of the
to have led to conflicting NMR spectral assignments of the C-4
and C-10 methyl signals, but by using lithium aluminum deuteride to obtain the
deuterated analog we were able to prove, in agreement with
derived from
configura-
tion. Previous
that the
l
Wisconsin Section of the American Chemical Society postdoctoral fellow.
Maintained in cooperation with the University of Wisconsin.
From M.S. Thesis of J.W.F., University of Kansas, August 1970.
C. L.
and J. W. ROWE,
6, 151 (1967).
J. W. ROWE, C. L. BOWER, and E. R. WAGNER, Phytochem. 8,235 (1969).
J. W.
However, R. C. A.
boxylation of dehydroabietic acid on irradiation.
and P. G.
Org. Chem. 30, 1604 (1965).
Tetrahedron Letters 4127
reports oxidative free radical
This nomenclature is based on The Common and Systematic Nomenclature of Cyclic Diterpenes, 3rd
rev., October 1968, with addenda and corrigenda of February 1969, available from the Forest Products
Laboratory, Madison, Wis. 53705, U.S.A.
N.
and W. B. WATKINS, Tetrahedron 25,447 (1969).
R. C. R. A. and T. J. FULLERTON, Australian Chem.
Org. 35,478 (1970).
R.
(1969).
J. W.
1647

JOHN W. ROWE et al.
1648
chemical shift value of the C-4 methyl group lies
methyl group and not vice
ppm downfield from that of the C-10
In further studies on jack pine, we later isolated
(Ic) in
one-fourth the yield of the
Since appreciable amounts of
were undoubtedly lost
during attempted acetylation (which we have since found leads to extensive dehydration), the
natural occurrence of these two norabietatrienols parallels the 13 1 ratio of
we observe in the lead tetra-acetate decarboxylation of dihydropimaric acid.
Synthesis of Ic was achieved by treatment of
to
with
in aq. acetone followed by reduction with LAH of the intermediate
bromohydrin (presumably
diaxial addition of
resulting from
to the double bond). Attempts to obtain the corresponding
by reaction of the crude bromohydrin with alkali were unsuccessful. The
NMR spectrum of Ic shows the expected C-10 angular methyl resonance at
shielded by the
group, and the normal C-4 methyl signal at
4
R, =
=
;
3-ene
= OH
CH,
R
H
\
R
=
R = H
R =
R = O
In considering possible alternative routes to Ic it was thought that epoxidation of
might yield some of the desired However, as reported recently by Cambie and
the product of this reaction is essentially only the In agreement
with these authors, its reduction by LAH was found to proceed principally by axial attack”
at C-4 to yield
epimerizing conditions afforded the corresponding ketone
prepared, but by a different route.
Oxidation of
which
under
has also
Since both epimeric
are found in jack pine bark, it is reasonable to
expect that the three related
and
should also be present.
R. C. CAMBIE and R. A. FRANICH , Australian J. Chem.
Similar diaxial opening has been found with
(1970).
(1969).
by
R. C.
and W. A. DENNY,
J. Chem.

1650
JOHN W. ROWE et al.
fractions. The noncarbonyl fraction was chromatographed on 500 g of silica. Benzene eluted 386 mg of
yellow oil which consisted of a mixture of three diterpenes by GLC. The mixture was separated by prepara-
tive GLC on
and SE-52. The smallest component (21 ma) was distilled.
and had IR and NMR spectra with those of the synthetic sample
(tertiary OH). The high resolution mass spectrum was run by Professor Ralph C. Dougherty
mm) 150”.
(c
3615
at Florida State University. It showed a strong molecular ion at 272.2133 corresponding to
272.2140). Also significantly strong were the peaks corresponding to the loss of the
or both at
as propene to give an ion at m/e 197 or by loss of butadiene representing C-2, C-3, C-4, and
ion at m/e
257,254, and 239. The m/e 239 fragment then further degraded by loss of the isopropyl group
to give an
This fragmentation is in agreement with the reported data on the mass spectra of aromatic
7-Oxodehydroabietyl Acetate
The eluate of 5.93 g was crystallized from hexane and
distilled to yield 3.485 g of oil, b.p.
to remove triterpenes, acetylated, and
mm) 158-248”. This was chromatographed on 250 g of
Elution
with benzene yielded 583 mg of oil, GLC (SE-30) of which showed a major and a minor component. The
minor component (34 mg) was isolated by preparative-scale GLC. The NMR, IR and UV spectra correspond
to those of a synthetic sample of
acetate
Western White Pine
The benzene extract of western white pink
was processed as usual to yield the nonsaponifiable
fraction (14.9% of the benzene extract). Chromatography on alumina yielded
of the benzene extract) which were rechromatographed on 260 g of 40
g of hydrocarbons”
on Woelm alumina.
Light petroleum-benzene (95 5) eluted 32 mg of a mixture of hydrocarbons, a minor one of which (0.0002
of the benzene extract) had the identical retention time on GLC (SE-30, DEGS) and an identical R, on
argentian TLC as synthetic
The same solvent later removed 38 mg of a mixture of hydrocarbons, one of which
benzene extract) had the identical retention time on GLC (SE-30, DEGS) and an identical
TLC as synthetic
of the
on argentian
Light petroleum-benzene 3 eluted 74 mg of 54% pure hydrocarbon
with aretention time on GLC (SE-30, was to that of
13-tetraene (Ila). This was purified by preparative GLC and distillation, b.p.
(c (reported:
of the benzene extract)
mm)
It gave a single peak on GLC and a single spot
on argentian TLC identical to the synthetic hydrocarbon. Their
and NMR spectra were superimposable.
Synthesis of Reference Compounds
Preparative separation of the
-4, and
of dehydroabietic
(Ha,
and
formed in
the lead tetra-acetate decarboxylation
was readily achieved by chromatography
on 20 silver nitrate-alumina activated overnight at 140”. From
g of the tetraene mixture adsorbed on a
50 x 2-cm column,
g of the
g of the
and
g of the
(Ha) were
obtained by successive elution with light petroleum, light petroleum-Et20 (3: and
spectral properties of each isomer were in substantial agreement with those
respectively. The
(la)
Epoxidation of
thalic acid in
g
mmol) of the
in 10 ml of
at 25” by 2 ml of
M
was nearly complete after hr provided the
was evaporated from the mixture after
the oxidizing agent was added. For reduction, the resulting (crude)
was dissolved, in 15 ml of dry
and stirred at 25” for 24 hr with
g of fresh
Chromato-
graphy of the neutral product on 15 g of silica gel and elution with light
olefinic material and then 80 mg of
(4: 1) gave 17 mg of
(la), which crystallized on standing.
yield) of analytically pure as small
Recrystallization from light petroleum at -70” afforded 70 mg (65
white spores: m.p. 89-91” (lit. m.p.
90-91”
[a]
(lit.’
IR
3614 and 3460 cm-’ (-O-H); NMR
8.91 (C-10 Me), 8.85 (C-4 Me), and
(i-Pr
and
C. R. ENZELL and I. WAHLBERG,
W. C. NICKLES and J. W. ROWE, Forest Products J. 12, 374 (1962).
This fraction was also found to contain
abietatetraene,
H. H. ZEISS and W. B. MARTIN , J. Am. Chem.
Prepared from dehydroabietonitrile and purified through the methyl ester [cf. A. W.
L. R.
Chem.
23, 871 (1969).
cadalene,
and
(unpublished results).
75, 5935 (1953).
J. Am. Chem,
86, 96

Derivatives of nordehydroabietane from pine bark
1651
doublet,
mixture
=
(Found: C,
H,
for
C, 83.8; H,
Spectral and
comparison showed this material to be identical with a sample of
prepared by
reduction of 1
reaction.
acetate isolated from the lead tetra-acetate decarboxylation
Similar reduction of
of
g of the
with
m.p.
C-10 Me), 8.86
g of
IR
in 15 ml of dry
3614 and 3455
afforded 80 mg
(-O-H); 2180
(C-D); NMR 8.91
C-4
and
i-Pr doublet,
=
Hz).
(Zc)
g of N-bromoacetamide and
To a solution of
g of
in 20 ml
was added a solution
of
g
mmol) of
in 50 ml of acetone. The mixture was stirred
overnight at 25” and then evaporated under reduced pressure until most of the acetone was removed. An
additional 10 ml were added, and the mixture was extracted with The extract was dried (mole-
cular sieves) and evaporated under reduced pressure to give crude
and stirred for
Chromatography of the neutral product on 17g of silica gel furnished
as a yellow oil which could not be crystallized. The oil was dissolved in 30 ml of dry
24 hr at 25” with
of recovered
of
by elution with light petroleum and then 50 mg of
(Ic) by
elution with light
(5: 1). Further elution afforded only bromine-containing material. On
standing, Ic slowly crystallized, and on recrystallization from light petroleum at -70” had
65-67”:
(deshielded
for
(c 2.0,
NMR 8.82 (C-4 Me), 1.19 (i-Pr doublet,
=
Hz), and
compared to
C-10 Me). On TLC on silica gel with
9: 1, Ic showed
and Ib. The mass spectrum had a parent peak of m/e 272
= 272).
The
prepared by the action of perphthalic acid in
was dissolved in 20 ml of dry
on
g of
g of
tetraene
and refluxed for 4 with
in 30 ml of
dimethoxyethane. Chromatography of the neutral product on 25 g of silica gel afforded, by elution with light
g of
3675 and 3450
8.99 (C-10 Me), and 8.81 (i-Pr doublet,
as a viscous oil:
(c
IR
(-O-H); NMR
(C-4 Me doublet, = 5 Hz),
=
Hz).
Oxidation of 75 mg of
with Kiliani’s reagent according to the procedure of
with spectral properties as
gave 50 mg of
The
hydrazone after crystallization from
had m.p. and mixed m.p. 154-155” (lit.” 154-155”).
Acetate
The oily acetate of
prepared by reaction of the alcohol with
in pyridine
at 25” for 6 hr, was oxidized by a procedure similar to that reported for the oxidation of methyl
To a solution of
After standing at 25” for 18
The combined layers were washed with 5
g of the acetate in 5 ml
the mixture was diluted with saturated
then with
was added 6.25 g of a
abietate to the
derivative.
10%
in 80%
and
and dried
extracted with
Evaporation gave a yellow oil which was chromatographed on 45 g of neutral alumina
activity grade II). Elution with light
ing. Recrystallization from light petroleum furnished
acetate as colorless prisms: m.p.
and 303 nm (2040); IR 1740 (C==O, acetate), 1685
i-Pr doublet,
(4: 1) gave a light yellow oil which crystallized on stand-
g
of
(c
UV
7-keto group), and 1235
Hz), 8.76 Me),
C-18 AB-quartet, = 11 Hz).
207
253
(C-O); NMR
acetate), 7.46
(Found: C,
C-4 Me), 8.78
=
C-6
H, 8.7.
doublet, = 9 Hz), and 6.28
required: C, 77.2; H,
are grateful for the invaluable help of Jan K. Toda and Carol L. Bower, Forest
Products Laboratory, in the isolation of some of the natural products from jack pine bark. We thank
R. C. Cambie, University of Auckland, New Zealand, for a sample of
and W. B. Watkins, Oxford,
United Kingdom, and J. W.
Clemson University, South Carolina, U.S.A., for copies of the spectra
for a sample of and for the mixed melting point determina-
of
Added thanks are given J. W.
tion of the
of
la and
bark.
have also been found to comprise
each of the benzene extract of western white pine
solution they differ slightly from those
Because these chemical shift values were determined in
recorded in Refs. 6 and 8, which were measured in
E. WENKERT and B. G. J ACKSON , J. Am. Chem.
80,211 (1958).