Sesquiterpene constituents of the liverwort Calypogeia fissa

Article abstract of DOI:10.1016/S0031-9422(99)00321-0

Four new sesquiterpenes have been identified as constituents of the liverwort Calypogeia fissa: (+)-10β(H)-muurola-3,7(11)-dien-1-ol, (-)-α- alasken-6β-ol, (-)-α-alasken-8-one and 7,8-dehydro-α-acoradiene. (+)- Cadina-1(10),3,7(11)-triene and (+)-cis-cadina-4,6-dien-11-ol were obtained as reaction products from (+)-10β(H)-muurola-3,7(11)-dien-1-ol.

Full text of DOI:10.1016/S0031-9422(99)00321-0

Phytochemistry 52 (1999) 695±704
Sesquiterpene constituents of the liverwort Calypogeia ®ssa
Ute Warmers, Wilfried A. Konig*
Institut fur Organische Chemie, Universitat Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
È
È
Received 17 March 1999; received in revised form 17 May 1999; accepted 20 May 1999
Abstract
Four new sesquiterpenes have been identi®ed as constituents of the liverwort Calypogeia ®ssa: (+)-10b(H )-muurola-3,7(11)-
dien-1-ol, ( )-a-alasken-6b-ol, ( )-a-alasken-8-one and 7,8-dehydro-a-acoradiene. (+)-Cadina-1(10),3,7(11)-triene and (+)-cis-
cadina-4,6-dien-11-ol were obtained as reaction products from (+)-10b(H )-muurola-3,7(11)-dien-1-ol. # 1999 Elsevier Science
Ltd. All rights reserved.
Keywords: Calypogeia ®ssa; Jungermanniales; Liverwort; Sesquiterpene; (+)-10b(H)-muurola-3,7(11)-dien-1-ol; (+)-cadina-1(10),3,7(11)-triene;
(+)-cis-cadina-4,6-dien-11-ol; ( )-a-alasken-6b-ol; ( )-a-alasken-8-one; 7,8-dehydro-a-acoradiene
1. Introduction
as constituents of the essential oil of C. ®ssa: Maali-
1,3-diene (Warmers et al., 1998), anastreptene, cis-a-
bergamotene, a-cedrene, b-cedrene, 10(14)-aromaden-
drene, 7,8-dehydro-a-acoradiene, a-acoradiene, ar-cur-
The Calypogeia species are leafy liverworts
(Hepaticae) of the order Jungermanniales (Frahm &
Frey, 1992). In previous reports we have investigated
the sesquiterpene constituents of several liverworts of
the Calypogeia family: C. muelleriana (Warmers,
Wihstutz, Bulow, Fricke & Konig, 1998) and C. sue-
cica (Warmers & Konig, in press). We now report on
the constituents of C. ®ssa.
cumene,
g-curcumene,
d-selinene,
allo-9-
aromadendrene, bicyclogermacrene, ledene, b-alaskene,
b-bisabolene, ( )-a-alaskene, ( )-maaliol, 4,5-dehydro-
viridi¯orol (Warmers et al., 1998), globulol, rosifoliol,
(+)-10b(H )-muurola-3,7(11)-dien-1-ol, ( )-a-alasken-
6b-ol and ( )-a-alasken-8-one (Fig. 1, Scheme 1). C.
®ssa was collected in the Harz mountains and in the
Black Forest, in Germany. The essential oils of both
plant samples showed only one di€erence: ( )-a-alas-
ken-8-one is solely a constituent of the liverwort col-
lected in the Harz.
2. Results and discussion
The essential oil of C. ®ssa was obtained by hydro-
distillation and analysed by gas chromatography (GC)
and GC-mass spectrometry (GC-MS). Individual com-
ponents were isolated by preparative GC and investi-
gated by NMR. The absolute con®guration was
derived by polarimetric measurements and enantiose-
lective GC using cyclodextrin phases. The structures of
the new compounds were veri®ed by chemical conver-
sions. The following compounds have been identi®ed
(+)-10b(H )-Muurola-3,7(11)-dien-1-ol {(4R,4aR,8a
R ) - 1,2,3,4,4a,5,8,8a - octahydro - 4,7 - dimethyl - 1 - (1-
methylethyliden)-naphthalen-4a-ol}(1)isanewsesquiter-
penealcohol.Themassspectrumexhibitedamolecularion
signal at m/z 220 and an elemental composition of
1
C15H24O. The H NMR spectrum showed a signal for
an ole®nic proton at d 5.27, singlets for three allylic
methyl groups at quaternary carbon atoms at d 1.64,
1.72 and 1.72 and a doublet for a secondary methyl
group at d 0.84.
* Corresponding author. Tel.: +49-40-4123-2824; fax: +49-40-
4123-2893.
E-mail address: wkoenig@chemie.uni-hamburg.de (W.A. Konig)
In the 13C NMR- and DEPT spectrum signals for
four primary carbons (d 14.83, 20.03, 20.65, 22.78),
0031-9422/99/$ - see front matter # 1999 Elsevier Science Ltd. All rights reserved.
PII: S0031-9422(99)00321-0

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U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
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group was connected to a second double bond system
consisting of a tertiary carbon (d 5.27, 118.73, CH-3),
a quaternary carbon (d 132.59, C-4) and a methyl
group (d 1.64, 22.78, CH3-15). The double bond sys-
tem further coupled with a methylene group (d 1.87,
2.18, 33.97, CH2 5), which was connected to the CH-
6 methine group. Combination of all these data led to
structure 1.
The relative con®guration of the stereogenic centres
at C-1, C-6 and C-10 was derived from a NOESY
spectrum. The saturation of the resonance of H-6
resulted in an increase of the signal intensities of H-5a
and H-2a, while H-10 interacted with H-5b, H-2b and
H-8b. Therefore the protons H-6 and H-10 have to be
on di€erent sides of the molecule. The observed inter-
actions were only possible for a cis-connected bicyclic
system (Fig. 2).
1 was dehydrated. The only dehydration product
was
2,3,4,4a,5,8-hexahydro-1,6-dimethyl-4-(1-methylethyli-
(+)-cadina-1(10),3,7(11)-triene
{(4aR )-
den)-naphthalene} (2), a new sesquiterpene hydro-
carbon (Fig. 3). The mass spectrum showed
molecular ion signal at m/z 202 and an elemental com-
a
1
position of C15H22. In the H NMR spectrum singlets
for four allylic methyl groups at quaternary carbon
atoms at d 1.64, 1.66, 1.70, 1.70 and a signal for an
ole®nic proton at d 5.38 were observed.
Fig. 1. Gas chromatogram of the essential oil of C. ®ssa on a 25 m
fused silica capillary with polysiloxane CpSil5; column temp. 508C,
temp. program 38/min to 2308C; carrier gas 0.5 bar H2.
An acid catalysed rearrangement reaction of 1
yielded (+)-cis-cadina-4,6-dien-11-ol (3), (+)-cadina-
1(10),3,7(11)-triene (2), (+)-cis-calamenene (4) and
( )-trans-calamenene (5) (Fig. 3). (+)-cis- (4) and ( )-
trans-calamenene (5) were identi®ed by GC-MS and by
comparison with a sample of both enantiomeric pairs
of cis- and trans-calamenene on cyclodextrin GC
four secondary carbons (d 24.23, 30.94, 33.97, 35.32),
three tertiary carbons (d 30.75, 44.45, 118.73) and four
quaternary carbons (d 72.61, 127.02, 130.14, 132.59)
were observed. The slightly low ®eld shifted signal at d
72.61 was assigned to a quaternary carbon bonded to
an oxygen. The strongly low ®eld shifted signals at d
127.02, 130.14 and 132.59 indicated the presence of
two ole®nic double bonds.
The HMQC spectrum showed the correlation of the
1H and the 13C NMR spectrum. The connection of the
groups was derived from the COSY GS- and the
HMBC spectrum.
One of the double bonds was exocyclic with two
allylic methyl groups (d 130.14, C-7; 127.02, C-11;
1.72, 20.03, CH3-12/13; 1.72, 20.65, CH3-12/13). The
ole®nic quaternary carbon atom was connected to a
methine group (d 2.96, 44.45, CH-6) and a chain of
two methylene groups (d 2.06, 2.52, 24.23, CH2-8;
1.22±1.31, 1.49±1.58, 30.94, CH2-9). The latter methyl-
ene group coupled with a methine group (d 1.75±1.83,
30.75, CH-10) bonded to a methyl group (d 0.84,
14.84, CH3-14) and to a quaternary carbon atom with
a hydroxy group (d 72.61, C-1). This carbon coupled
with the CH-6 methine group and with a methylene
group (d 1.98, 2.40, 35.32, CH2 2). This methylene
phases.
(+)-cis-Cadina-4,6-dien-11-ol
{(4R,4aS)-
2,3,4,4a,5,6-hexahydro-a,a,4,7-tetramethylnaphthalen-
1-methanol} (3) is a new sesquiterpene alcohol. The
mass spectrum exhibited a molecular ion signal at m/z
220 and an elemental composition C15H24O. The 1H
NMR spectrum showed a signal for an ole®nic proton
at d 5.28, a doublet for a secondary methyl group at d
0.75 and singlets for three tertiary methyl groups at d
1.26, 1.39 and 1.71. The strongly low ®eld shifted sig-
nal at d 1.71 indicated an allylic methyl group; the
slightly low ®eld shifted signals at d 1.26 and 1.39 were
assigned to two methyl groups next to oxygen.
The absolute con®guration of 1, 2 and 3 was
obtained by a correlation reaction with (+)-d-cadinene
(6), which was isolated from the liverwort Calypogeia
muelleriana (Warmers et al., 1998). After catalytic
hydrogenation of 2 and 6 (Fig. 4) four hydrogenation
products of 2 had the same GC-MS characteristics and
the same retention times on achiral GC phases, but
di€erent retention times on chiral cyclodextrin derived
GC phases compared to the hydrogenation products
of 6. Hence, the relative con®guration of these satu-

U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
È
697
Scheme 1.

698
U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
È
Fig. 2. NOE e€ects of 10b(H )-muurola-3,7(11)-dien-1-ol (1), a-alasken-6b-ol (7) and a-alasken-8-one (10).
Fig. 3. Dehydration of (+)-10b(H)-muurola-3,7(11)-dien-1-ol (1) to (+)-cadina-1(10),3,7(11)-triene (2) and acid rearrangement of (1) to (+)-
cadina-1(10),3,7(11)-triene (2), (+)-cis-cadina-4,6-dien-11-ol (3), (+)-cis-calamenene (4) and ( )-trans-calamenene (5).

U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
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699
Fig. 4. Hydrogenation of (+)-Cadina-1(10),3,7(11)-triene (2) and (+)-d-cadinene (6).
rated cadinanes had to be identical, while the absolute
con®guration was opposite.
nal for an ole®nic proton at d 5.22, a proton next to
oxygen at d 4.75, singlets for three allylic methyl
groups at quaternary carbon atoms at d 1.70 and 1.83
and a doublet for a secondary methyl group at d 1.08
were observed.
From the 13C NMR- and DEPT spectrum signals
for four primary carbons (d 18.00, 19.49, 23.08, 24.51),
( )-a-Alasken-6b-ol {(1R,5R,6R )-1,8-dimethyl-4-(1-
methylethyliden)-spiro[4.5]dec-8-en-6-ol} (7) is another
new sesquiterpene alcohol. The mass spectrum showed
a molecular ion signal at m/z 220 and an elemental
1
composition C15H24O. In the H NMR spectrum a sig-

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U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
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four secondary carbons (d 30.63, 30.90, 35.90, 37.22),
three tertiary carbons (d 39.39, 71.97, 119.97) and four
quaternary carbons (d 54.09, 124.49, 132.92, 137.35)
could be derived. The slightly low ®eld shifted signal
at d 71.97 indicated a carbon next to oxygen. The
strongly low ®eld shifted signals at d 119.97, 124.49,
132.92 and 137.35 were assigned to two double bonds.
The NMR spectra of 7 resembled those of a-alas-
kene (8) (Andersen & Syrdal, 1970,1972; Andersen,
Costin, Kramer & Ohta, 1973), another constituent of
C. ®ssa, except for the low ®eld shift of the signals of
the protons and carbons next to the oxygen at C-6.
The relative con®guration of the stereogenic centres
at C-1, C-6 and C-10 were derived from a NOESY
spectrum. H-14 interacted with H-5b and H-6 with H-
5a, H-2a and H-12 (Fig. 2).
showed a signal for an ole®nic proton at d 5.34, sing-
lets for three allylic methyl groups at quaternary car-
bon atoms at d 1.70, 1.93 and 2.23 and a doublet for a
secondary methyl group at d 0.94.
From the 13C NMR- and DEPT spectrum signals
for four primary carbons (d 16.77, 23.46, 23.54, 23.89),
four secondary carbons (d 27.85, 27.99, 34.38, 45.73),
two tertiary carbons (d 33.59, 119.93) and ®ve quatern-
ary carbons (d 46.35, 134.68, 138.31, 149.49, 208.62)
could be derived. The very strongly low ®eld shifted
signal at d 208.62 indicated a carbonyl group; the
other low ®eld shifted signals at d 119.93, 134.68,
138.31 and 149.49 were assigned to four ole®nic car-
bon atoms.
Additional information could be obtained from
COSY GS- and HMBC spectra. One of the double
bond system represented an exocyclic double bond
with two allylic methyl groups (d 138.31, C-7; 149.49,
C-11; 1.93, 23.54, CH3-12; 2.23, 23.89, CH3-13), which
was connected to a quaternary carbon atom (d 46.35,
C-1) and to the carbonyl carbon (d 208.62, C-8). The
carbonyl carbon further coupled to a methylene group
(d 1.91, 2.53, 45.73, CH2-9). This methylene group was
bonded to a methine group (d 2.05±2.14, 33.59, CH-
10), which coupled with a methyl group (d 0.94, 16.77,
CH3-14) and the C-1 carbon. This carbon was a spiro
The dehydration of 7 with thionylchloride gave a
product, which should be 5,6-dehydro-a-alaskene
{(1R,5S )-1,8-dimethyl-4-(1-methylethyliden)-spiro[4.5]-
deca-6,8-diene} (9) (Fig. 5). It was characterised only
by GC-MS.
( )-a-Alasken-8-one {(4R,5S)-4,8-dimethyl-1-(1-
methylethyliden)-spiro[4.5]-dec-7-en-2-one} (10) is
a
new sesquiterpene ketone. The mass spectrum exhib-
ited a molecular ion signal at m/z 218 and an elemen-
1
tal composition of C15H22O. The H NMR spectrum
Fig. 5. Dehydration of ( )-a-alasken-6b-ol (7) to 5,6-dehydro-a-alaskene (9) and reduction of ( )-a-alasken-8-one (10) to a-alasken-8a-ol (11)
and a-alasken-8b-ol (12) and dehydration to 7,8-dehydro-a-acoradiene (13).

U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
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701
Fig. 6. Hydrogenation of ( )-a-alasken-6b-ol (7), 7,8-dehydro-a-acoradiene (13) and ( )-a-alaskene (8).
centrum, which further coupled with two methylene
groups (d 2.05±2.14, 2.16±2.24, 34.38, CH2-2; 1.71±
1.75, 1.74±1.79, 27.99, CH2-6). The CH2-2 methylene
group was connected to a second double bond system
with a methine group and a quaternary carbon carry-
ing a methyl group (d 5.34, 119.93, CH-3; 134.68, C-4;
1.70, 23.46, CH3-15). This double bond system further
coupled with a chain of two methylene groups (d 2.05±
2.14, 2.05±2.14, 27.85, CH2-5; 1.71±1.75, 1.74±1.79,
27.99, CH2-6). The combination of all these data led
to structure 10.
The absolute con®guration of 7, 9, 10, 11, 12 and 13
was obtained by a correlation reaction with ( )-a-alas-
kene (8), another constituent of C. ®ssa.
Hydrogenation of 7, 13 and 8 yielded four identical
saturated acoranes, which had the same MS and reten-
tion times on achiral and chiral GC phases (Fig. 6).
Hence, the relative and absolute con®guration had to
be identical.
The identi®cation of the sesquiterpene constituents is
of chemotaxonomic relevance and may serve as an
alternative in identifying closely related liverworts, es-
pecially for C. ®ssa and C. muelleriana, which show
only minor morphological di€erences. While com-
pounds with the aromadendrane skeleton and azule-
noids are characteristic for C. muelleriana and
compounds with the bisabolane skeleton for C. sue-
cica, the essential oil of C. ®ssa is dominated by acor-
ane type sesquiterpenes. Azulenes are considered as
signi®cant chemical indicators of Calypogeia species
(Asakawa, 1995), but in C. ®ssa and C. suecica no azu-
lenes could be detected.
In the NOESY spectrum of 10 interactions of H-14
with H-6b and H-9a were observed. The saturation of
the resonance of H-12 resulted in an increase of the
signal intensity of H-2a (Fig. 2).
10 was reduced to two diastereomeric alcohols: a-
alasken-8a-ol (11) and a-alasken-8b-ol (12), {(2R/
S,4R,5S )-4,8-dimethyl-1-(1-methylethyliden)-spiro[4,5]-
dec-7-en-2-ol}, which easily dehydrated to 7,8-dehy-
dro-a-acoradiene {(1R,5S )-1,8-dimethyl-4-(methylethe-
nyl)-spiro[4.5]deca-3,7-diene} (13), a new sesquiterpene
hydrocarbon, which was also present in the essential
oil of C. ®ssa (Fig. 5). The mass spectrum exhibited a
molecular ion signal at m/z 202 and an elemental com-
1
position of C15H22. The H NMR spectrum showed a
3. Experimental
doublet for a secondary methyl group at d 0.91, sing-
lets for two allylic methyl groups at quaternary car-
bons at d 1.67 and 1.89, signals for two geminal
ole®nic protons at d 4.84 and 4.92 and for two ad-
ditional ole®nic protons at d 5.33 and 5.62.
3.1. Plant material
Calypogeia ®ssa was collected in the Harz, near
Sieber and in the Black Forest, near Gaggenau

702
U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
È
(Germany). It was identi®ed by R. Mues, Universitat
des Saarlandes, Saarbrucken, Germany.
J = 12.1 Hz, H-5b), 2.40 (1H, dd, J = 4.0, 16.0 Hz,
H-2b), 2.52 (1H, dm, J = 15.0 Hz, H-8a), 2.96 (1H,
dd, J = 6.7, 12.1 Hz, H-6), 5.27 (1H, d, J = 4.0 Hz,
H-3); 13C NMR (125 MHz, CDCl3): d 14.83 (q, C-14),
20.03 (q, C-12/13), 20.65 (q, C-12/13), 22.78 (q, C-15),
24.23 (t, C-8), 30.75 (d, C-10), 30.94 (t, C-9), 33.97 (t,
C-5), 35.32 (t, C-2), 44.45 (d, C-6), 72.61 (s, C-1),
118.73 (d, C-3), 127.02 (s, C-11), 130.14 (s, C-7),
132.59 (s, C-4); MS (EI, 70 eV): m/z (rel.int.) 220 (<1)
[M+], 202 (19) [M+±H2O], 187 (10) [M+±H2O±CH3],
159 (14), 153 (11), 152 (100), 146 (9), 145 (7), 137 (34),
134 (6), 133 (13), 131 (5), 119 (11), 109 (9), 107 (6),
105 (8), 95 (7), 93 (6), 91 (11), 81 (7), 79 (8), 77 (8), 67
(9), 55 (8), 53 (8), 43 (9), 41 (20), 39 (9).
3.2. Hydrodistillation
The essential oil was prepared by hydrodistillation
(2 h) of aqueous homogenates of fresh and green
plants using n-hexane as collection solvent. Because of
the greatly di€ering drying state of the fresh plants the
material was not weighed.
3.3. Gas chromatography
Orion Micromat 412 double column instrument with
25 m fused silica capillaries with polysiloxane CpSil 5
and polysiloxane CpSil 19 (Chrompack); Carlo Erba
Fractovap 2150, 4160 column instruments with 25 m
fused silica capillaries with heptakis(2,6-di-O-methyl-3-
O-pentyl)-b-cyclodextrin or heptakis(6-O-tert-butyldi-
methylsilyl-2,3-di-O-methyl)-b-cyclodextrin in OV 1701
(50%, w/w); split injection; ¯ame ionization detection;
carrier gas 0.5 bar H2.
3.9. Dehydration of (+)-10b(H)-muurola-3,7(11)-
dien-1-ol (1) to (+)-cadina-1(10),3,7(11)-triene (2)
To a sol. of 1mg of 1 in 1ml pyridine 0.1ml SOCl2
was added and the reaction mixture was stirred at 08C
for 10 min. n-Hexane and H2O were added. The or-
ganic phase was washed three times with H2O. The
reaction product was isolated by preparative GC. - 2:
1H NMR (500 MHz, CDCl3): d 1.64 (3H, s, H-14),
1.66 (3H, s, H-15), 1.70 (6H, s, H-12, H-13), 1.89±2.06
(5H, m, H-5a/b, H-8a, H-8b, H-9a, H-9b), 2.56±2.62
(1H, m, H-5a/b), 2.59±2.65 (1H, m, H-2a/b), 2.94 (1H,
bd, J = 19.3 Hz, H-2a/b), 3.12 (1H, dd (t), J = 8.2
Hz, H-6), 5.38 (1H, bs, H-3); MS (EI, 70 eV): m/z
(rel.int.) 202 (100) [M+], 188 (9), 187 (59) [M+±CH3],
183 (9), 160 (10), 159 (56), 147 (10), 145 (41), 143 (11),
133 (10), 132 (13), 131 (40), 129 (12), 128 (12), 119
(35), 117 (17) 115 (12), 107 (11), 105 (33), 93 (9), 91
(27), 79 (10), 77 (15), 55 (10), 41 (26), 39 (14).
3.4. Isolation
The isolation was carried out using preparative GC.
3.5. Preparative GC
Modi®ed Varian 1400 instrument, equipped with a
stainless steel column (1.85 m  4.3 mm) with 10%
polydimethylsiloxane SE 30 on Chromosorb W-HP;
¯ame ionization detection; helium as carrier gas at a
¯ow rate of 240 ml/min (Hardt & Konig, 1994).
3.6. NMR spectroscopy
3.10. Acid rearrangement of (+)-10b(H )-muurola-
3,7(11)-dien-1-ol (1) to (+)-cadina-1(10),3,7(11)-
triene (2), (+)-cis-cadina-4,6-dien-11-ol (3), (+)-cis-
calamenene (4) and ( )-trans-calamenene (6)
NMR measurements were carried out with a Bruker
WM 400 or a Bruker WM 500 instrument using TMS
as internal standard.
To a sol. of 1 mg of 1 in 1ml n-hexane 0.5 mg
Amberlyst 15 were added. The reaction mixture was
stirred at room temp. for 2 h and for additional two
days. After 2 h reaction time 2 and 3 were the major
products. After two days only 4 and 5 were found. 4
and 5 were identi®ed by GC-MS and by comparison
with a sample of both enantiomeric pairs of cis- and
trans-calamenene on cyclodextrin GC phases. 2 and 3
were isolated by preparative GC. 3: 1H NMR (500
MHz, CDCl3): d 0.75 (3H, d, J = 6.3 Hz, H-14), 1.26
(3H, s, H-12/13), 1.29-1.38 (1H, m, H-8/9), 1.39 (3H,
s, H-12/13), 1.49-1.58 (1H, m, H-8/9), 1.58-1.77 (3H,
m, H-8/9, H-8/9, H-10), 1.71 (3H, bs, H-15), 1.91-1.99
(1H, dm, J = 12.0 Hz, H-3), 2.01 (1H, dd, J = 15.0,
5.1 Hz, H-2), 2.16 (1H, dd (t), J = 15.0 Hz, H-2),
2.39-2.47 (2H, m, H-3, H-1), 5.28 (1H, d, J = 5.3 Hz,
3.7. Mass spectrometry
GC-MS measurements (EI, 70 eV) were carried out
with a Hewlett Packard HP 5890 gas chromatograph
coupled to a VG Analytical 70-250S mass spec-
trometer.
3.8. (+)-10b(H)-Muurola-3,7(11)-dien-1-ol (1)
1H NMR (500 MHz, CDCl3): d 0.84 (3H, d, J = 6.6
Hz, H-14), 1.22±1.31 (1H, m, H-9a/b), 1.49±1.58 (1H,
m, H-9a/b), 1.64 (3H, s, H-15), 1.72 (6H, s, H-12, H-
13), 1.75±1.83 (1H, m, H-10), 1.87 (1H, dd, J = 6.7,
12.1 Hz, H-5a), 1.98 (1H, dm, J = 16.0 Hz, H-2a),
2.06 (1H, bt, J = 15.0 Hz, H-8b), 2.18 (1H, bt,

U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
È
703
H-5); MS (EI, 70 eV): m/z (rel.int.) 220 (24) [M+], 205
(9) [M+-CH3], 202 (6) [M+-H2O], 187 (3) [M+-H2O-
CH3], 163 (25), 162 (11), 159 (16), 147 (10), 145 (11),
133 (10), 132 (11), 121 (12), 119 (28), 110 (41), 109
(100), 108 (78), 107 (14), 106 (11), 105 (29), 95 (26), 93
(24), 92 (11), 91 (30), 81 (19), 80 (12), 79 (21), 77 (21),
69 (33), 67 (19), 56 (15), 55 (26), 53 (19), 43 (24), 41
(58), 39 (23).
(3H, s, H-12), 1.67±1.75 (1H, m H-9a/b), 1.79±1.87
(1H, m, H-5a/b), 1.87±1.92 (1H, m, H-10), 1.91-1.99
(1H, m, H-2a/b), 1.97±2.04 (2H, m, H-5a/b, H-6a),
2.11 (1H, dm, J = 17.7 Hz, H-2a/b), 2.21±2.29 (1H,
m, H-8a/b), 2.29±2.39 (1H, m, H-8a/b), 5.32 (1H, bs,
H-3); 13C NMR (125 MHz, CDCl3): d 15.66 (q, C-14),
20.22 (q, C-12), 23.55 (q, C-15), 23.96 (q, C-13), 27.60
(t, C-6), 28.60 (t, C-5), 29.82 (t, C-9), 30.42 (t, C-8),
35.06 (t, C-2), 41.12 (d, C-10), 46.66 (s, C-1), 120.75
(d, C-3), 122.65 (s, C-11), 134.28 (s, C-4), 140.69 (s, C-
7); MS (EI, 70 eV): m/z (rel.int.) 204 (13) [M+], 189
(2) [M+±CH3], 161 (10), 137 (6), 136 (58), 122 (10),
121 (100), 119 (6), 107 (6), 105 (8), 93 (10), 79 (7), 55
(4), 53 (4), 41 (10).
3.11. Hydrogenation of (+)-cadina-1(10),3,7(11)-
triene (2)
To a sol. of 0.5 mg of 2 in 1 ml n-hexane 0.3 mg
Pd/C were added. The suspension was treated with H2
and stirred under H2 at room temp. for 1 h. The reac-
tion product was ®ltered and analysed by GC-MS and
by GC on several capillary columns with cyclodextrin
phases.
3.15. Dehydration of ( )-a-alasken-6b-ol (7) to 5,6-
dehydro-a-alaskene (9)
The dehydration of 7 was performed analogously to
the dehydration of 1. The reaction products were ana-
lysed by GC-MS. 9 was the main reaction product. 9:
MS (EI, 70 eV): m/z (rel. int.) 202 (24) [M+], 187 (32)
[M+±CH3], 173 (14), 161 (19), 159 (40), 147 (17), 146
(20), 145 (80), 133 (15), 132 (28), 131 (53), 129 (16),
128 (16), 120 (15), 119 (75), 117 (24), 115 (20), 107
(32), 106 (26), 105 (100), 95 (10), 93 (24), 92 (24), 91
(64), 81 (15), 79 (25), 77 (40), 68 (16), 67 (19), 65 (21),
55 (28), 53 (29), 41 (66).
3.12. Hydrogenation of (+)-d-cadinene (6)
The hydrogenation of 6 was performed analogously
to the hydrogenation of 2. The reaction products were
analysed by GC-MS and by GC on various capillary
columns with cyclodextrin phases. The hydrogenation
products of 6 and 2 were compared. Some of the
major constituents of the obtained saturated cadinanes
show identical retention times on achiral GC phases,
but di€erent retention times on chiral GC phases.
3.16. ( )-a-Alasken-8-one (10)
3.13. ( )-a-Alasken-6b-ol (7)
1H NMR (500 MHz, CDCl3): d 0.94 (3H, d, J = 7.0
Hz, H-14), 1.70 (3H, s, H-15), 1.71±1.75 (1H, dm,
J = 14.5 Hz, H-6b), 1.74±1.79 (1H, m, H-6a), 1.91
(1H, dd, J = 17.5, 2.9 Hz, H-9a), 1.93 (3H, s, H-12),
2.05±2.14 (4H, m, H-2b, H-5a, H-5b, H-10), 2.16±2.24
(1H, m, H-2a), 2.23 (3H, s, H-13), 2.53 (1H, dd,
J = 17.5, 7.9 Hz, H-9b), 5.34 (1H, bs, H-3); 13C NMR
(125 MHz, CDCl3): d 16.77 (q, C-14), 23.46 (q, C-15),
23.54 (q, C-12), 23.89 (q, C-13), 27.85 (t, C-5), 27.99
(t, C-6), 33.59 (d, C-10), 34.38 (t, C-2), 45.73 (t, C-9),
46.35 (s, C-1), 119.93 (d, C-3), 134.68 (s, C-4), 138.31
(s, C-7), 149.49 (s, C-11), 208.62 (s, C-8); 1H NMR
(500 MHz, C6D6): d 0.78 (3H, d, J = 7.0 Hz, H-14),
1.57±1.63 (1H, m, H-6), 1.65 (6H, s, H-12, H-15),
1.66±1.74 (1H, m, H-6), 1.83±1.92 (2H, m, H-9, H-10),
1.83±1.94 (2H, m, H-5a, H-5b), 1.90±1.98 (1H, m, H-
2), 2.05±2.12 (1H, m, H-2), 2.37 (3H, s, H-13), 2.40
(1H, dd, J = 17.5, 7.9 Hz, H-9), 5.26 (1H, bs, H-3);
13C NMR (125 MHz, C6D6): d 16.64, 23.11, 23.50,
23.70, 27.93, 28.17, 33.72, 34.51, 45.69, 46.27, 120.44,
134.23, 138.45, 147.89, 206.48; MS (EI, 70 eV): m/z
(rel.int.) 218 (28) [M+], 203 (3) [M+±CH3], 197 (2),
177 (9), 151 (11), 150 (100), 136 (8), 135 (81), 121 (8),
107 (33), 105 (13), 93 (10), 91 (27), 79 (20), 77 (20), 65
(10), 53 (15), 41 (31), 39 (20).
1H NMR (400 MHz, CDCl3): d 1.08 (3H, d, J = 7.1
Hz, H-14), 1.24±1.32 (1H, m, H-9a), 1.70 (6H, s, H-
13, H-15), 1.72±1.80 (1H, m, H-9b), 1.83 (3H, bs, H-
12), 2.02 (1H, dd, J = 4.6, 17.3 Hz, H-2b), 2.08±2.15
(1H, m, H-2a), 2.12±2.19 (1H, m, H-10), 2.18±2.29
(1H, m, H-5a), 2.25±2.35 (1H, m, H-8a/b), 2.27±2.37
(1H, m, H-5b), 2.36±2.47 (1H, m, H-8a/b), 4.57 (1H,
dd, J = 5.6, 10.4 Hz, H-6), 5.22 (1H, bs, H-3); 13C
NMR (125 MHz, CDCl3): d 18.00 (q, C-14), 19.49 (q,
C-12), 23.08 (q, C-13), 24.51 (q, C-15), 30.63 (t, C-9),
30.90 (t, C-8), 35.90 (t, C-5), 37.22 (t, C-2), 39.39 (d,
C-10), 54.09 (s, C-1), 71.97 (d, C-6), 119.97 (d, C-3),
124.49 (s, C-11), 132.92 (s, C-4), 137.35 (s, C-7); MS
(EI, 70 eV): m/z (rel.int.) 220 (7) [M+], 202 (12) [M+-
H2O], 187 (9) [M+±H2O±CH3], 159 (17), 153 (11), 152
(100), 145 (12), 137 (17), 131 (9), 123 (29), 121 (11),
119 (14), 109 (9), 105 (17), 91 (14), 81 (15), 77 (10), 67
(9), 55 (8), 41 (17).
3.14. ( )-a-Alaskene (8)
1H NMR (500 MHz, CDCl3): d 0.87 (3H, d, J = 7.0
Hz, H-14), 1.25±1.33 (1H, m, H-9a/b), 1.53±1.61 (1H,
m, H-6b), 1.62 (3H, s, H-13), 1.67 (3H, s, H-15), 1.70

704
U. Warmers, W.A. Konig / Phytochemistry 52 (1999) 695±704
È
3.17. Reduction of ( )-a-alasken-8-one (10) to a-
alasken-8a-ol (11) and a-alasken-8b-ol (12)
to the hydrogenation of 2. The reaction products were
analysed by GC-MS and by GC on various capillary
columns with cyclodextrin phases.
To a sol. 1 mg of 10 in 1ml methanol were added at
08C 1 mg of NaBH4. The mixture was stirred at 08C
for 1 h. The reaction was quenched by the addition of
a drop of 1M HCl. n-Hexane was added and the or-
ganic phase was washed with 1M HCl and H2O. The
reaction products were analysed by GC-MS. 11/12:
MS (EI, 70 eV): m/z (rel. int.) 202 (35) [M+±H2O],
187 (17) [M+±H2O±CH3], 174 (18), 159 (21), 152 (14),
145 (26), 137 (21), 134 (61), 133 (13), 123 (30), 121
(50), 119 (100), 109 (15), 105 (33), 95 (17), 93 (21), 91
(51), 79 (29), 77 (37), 67 (21), 59 (16), 55 (23), 53 (28),
43 (95), 41 (62), 39 (35). 11/12: MS (EI, 70 eV): m/z
(rel. int.) 202 (45) [M+±H2O], 187 (26) [M+±H2O±
CH3], 174 (33), 159 (38), 151 (31), 145 (26), 136 (32),
134 (75), 121 (95), 119 (100), 105 (33), 93 (22), 91 (40),
79 (22), 77 (27), 73 (21), 67 (13), 55 (18), 53 (19), 43
(28), 41 (42), 39 (21).
3.21. Hydrogenation of ( )-a-alaskene (8)
The hydrogenation of 8 was performed analogously
to the hydrogenation of 2. The reaction products were
analysed by GC-MS and by GC on various capillary
columns with cyclodextrin phases. The hydrogenation
products of 7, 8 and 13 were compared. They have
idential retention times on achiral and chiral GC
phases.
Acknowledgements
We are indebted to Prof. Dr. R. Mues, Universitat
des Saarlandes, Saarbrucken, for the identi®cation of
liverworts, to the Freie and Hansestadt Hamburg for a
scholarship to U. W. and to Dr. V. Sinnwell,
Universitat Hamburg, for his e€orts with the NMR
measurements.
3.18. Dehydration of a-alasken-8a-ol (11) and a-
alasken-8b-ol (12) to 7,8-dehydro-a-acoradiene (13)
11 and 12 were dehydrated during isolation by pre-
1
parative GC. 13: H NMR (400 MHz, CDCl3): d 0.91
References
(3H, d, J = 6.6 Hz, H-14), 1.67 (3H, bs, H-15/12),
1.89 (3H, s, H-12/15), 2.21 (1H, dm, J = 17.8 Hz),
2.48 (1H, ddd, J = 17.7, 7.4, 2.8 Hz), 4.84 (1H, s, H-
13), 4.92 (1H, s, H-13), 5.33 (1H, m, H-3/8), 5.62 (1H,
dd (t), J = 2.8 Hz, H-3/8); MS (EI, 70 eV): m/z (rel.
int.) 202 (26) [M+], 187 (11) [M+±CH3], 159 (9), 145
(26), 134 (42), 120 (12), 119 (100), 106 (15), 105 (28),
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3.19. Hydrogenation of ( )-a-alasken-6b-ol (7)
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lysed by GC-MS and by GC on various capillary col-
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Warmers, U., Wihstutz, K., Bulow, N., Fricke, C., & Konig, W. A.
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3.20. Hydrogenation of 7,8-dehydro-a-acoradiene (13)
The hydrogenation of 13 was performed analogously
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