Synthetic transformations of higher terpenoids: XVI. Synthesis of decahydronaphtho[1,2-g]indoles from lambertianic acid

Article abstract of DOI:10.1134/s1070428008010089

Oxidative methoxylation of 8,17-isopropylidenedioxy derivative of lambertianic acid methyl ester with N-chlorobenzenesulfonamide in methanol, followed by hydrogenation over Raney nickel, gave rise to a 2,5- dimethoxytetrahydrofuran fragment which was converted into N-substituted pyrrole ring by the action of amines in acetic acid. The subsequent removal of the acetonide protection and periodate cleavage of the diols thus formed resulted in the formation of 17-nor-8-oxo derivatives, and the latter underwent smooth cyclization to decahydronaphtho[1,2-g]indoles in acid medium.

Full text of DOI:10.1134/s1070428008010089

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2008, Vol. 44, No. 1, pp. 67–75. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © S.V. Chernov, E.E. Shul’ts, M.M. Shakirov, G.A. Tolstikov, 2008, published in Zhurnal Organicheskoi Khimii, 2008, Vol. 44, No. 1,
pp. 74–81.
Synthetic Transformations of Higher Terpenoids:
XVI.* Synthesis of Decahydronaphtho[1,2-g]indoles
from Lambertianic Acid
S. V. Chernov, E. E. Shul’ts, M. M. Shakirov, and G. A. Tolstikov
Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences,
pr. Akademika Lavrent’eva 9, Novosibirsk, 630090 Russia
e-mail: schultz@nioch.nsc.ru
Received October 31, 2006
Abstract—Oxidative methoxylation of 8,17-isopropylidenedioxy derivative of lambertianic acid methyl ester
with N-chlorobenzenesulfonamide in methanol, followed by hydrogenation over Raney nickel, gave rise to
a 2,5-dimethoxytetrahydrofuran fragment which was converted into N-substituted pyrrole ring by the action of
amines in acetic acid. The subsequent removal of the acetonide protection and periodate cleavage of the diols
thus formed resulted in the formation of 17-nor-8-oxo derivatives, and the latter underwent smooth cyclization
to decahydronaphtho[1,2-g]indoles in acid medium.
DOI: 10.1134/S1070428008010089
We previously [2] proposed a convenient procedure
for the synthesis of pyrrole-containing labdanoids from
lambertianic acid (I). We were interested in obtaining
on this basis terpenoid indoles as analogs of tremoro-
genic indole alkaloids (such as penitrems and paspa-
lines) [3] and biologically active polycyclic naphtho-
carbazoles [4–6]. For this purpose, we planned to use
the transformation of dioxolane II which is readily
available from lambertianic acid (I) [7] into the corre-
sponding N-substituted pyrroles according to Clauson-
Kaas [8] and their subsequent conversion into naphtho-
[1,2-g]indole derivatives.
IIIa–IIId in almost quantitative yield (Scheme 1). The
two cis and two trans stereoisomers were formed in
equal amounts, as followed from the intensities of sig-
nals from methoxy protons and 14-H, 15-H, and 16-H
1
in the H NMR spectra (the atom numbering accepted
for the labdane skeleton is used for compounds I–XI,
XIV–XVI, and XXI). Hydrogenation of IIIa–IIId
over Raney nickel afforded 2,5-dimethoxytetrahydro-
furan derivatives IVa–IVd which reacted with primary
amines in acetic acid to give 75–84% of the corre-
sponding N-alkylpyrroles V and VI. Prolonged reac-
tion resulted in the formation of diols VII and VIII.
8,17-Dihydroxy compounds IX–XI were synthesized
in 51–75% yield by reaction of 2,5-dimethoxytetrahy-
drofurans IVa–IVd with allylamine, benzylamine, and
aniline, respectively, on prolonged heating in acetic
acid. By periodate oxidation of diols VII and VIII in
methanol in the presence of acetic acid we obtained
decahydronaphtho[1,2-g]indoles XII and XIII in
a moderate yield (46–51%) as a result of cyclization of
intermediate 8-oxo-17-norlabdanoids. The oxidation of
IX–XI with sodium periodate under neutral conditions
gave 8-oxo-17-nor derivatives XIV–XVI (yield 76–
83%). Ketones XIV–XVI underwent intramolecular
ring closure to N-substituted decahydronaphtho[1,2-g]-
indoles XVII–XIX (yield 71–77%) on treatment with
acetic acid in methanol (Scheme 2), as it was reported
14
12
13
15
11
20Me
O
16
CH2
1
4
9
6
17
2
3
10
5
8
7
18
19
Me COOH
I
Compound II readily underwent oxidative meth-
oxylation by the action of N-chlorobenzenesulfon-
amide in methanol, which produced a mixture of
stereoisomeric 2,5-dimethoxydihydrofuran derivatives
* For communication XV, see [1].
67

CHERNOV et al.
68
Scheme 1.
OMe
OMe
O
O
O
Me
Me
Me
1O
O
O
O
PhSO2NHCl, MeOH
1'
OMe
OMe
+
7'
2
Me
Me
4a'
3'
Me
Me
O
5'
3O
Me
Me
Me COOMe
Me COOMe
OMe
Me COOMe
OMe
II
IIIa
IIIb
O
O
Me
O
Me
O
OMe
Me
OMe
Me
+
+
Me
Me
O
O
Me COOMe
Me COOMe
IIIc
IIId
Scheme 2.
OMe
O
N
H2/Raney Ni
MeOH
Me
Me
R
RNH2, H2O, AcOH
O
O
O
OMe
Me
Me
IIIa–IIId
Me
Me
O
Me COOMe
Me COOMe
V, VI
IVa–IVd
N
R
N
Me
Me
R
RNH2, H2O, AcOH
NaIO4, MeOH
O
OH
OH
IVa–IVd or V, VI
5
3
(for IX–XI)
7
1
Me COOMe
VII–XI
Me COOMe
XIV–XVI
1
11a
11
3b
1
10
9b
2
Me
3
N
NaIO4, H2O, MeOH, AcOH
MeOH, AcOH
3a
9
VII, VIII
9a
5a
8
7
R
4
6
5
12
13Me COOMe
XII, XIII, XVII–XIX
V, VII, XII, R = Me; VI, VIII, XIII, R = Et; IX, XIV, XVII, R = PhCH2; X, XV, XVIII, R = CH2=CHCH2; XI, XVI, XIX, R = Ph.
previously for 8-oxo-17-norlambertianic acid methyl
ester [7].
The natural labdane diterpenoid pinusolide (XX)
was shown to act as effective and specific platelet
aggregation inhibitor [9–11], as well as apoptosis-in-
ducing agent [12]. We have studied the possibility for
converting compounds IIIa–IIId into 8,17-isopropyli-
denedioxy pinusolide analog XXI. Our attempts to
synthesize butenolide XXI from IIIa–IIId under the
conditions described in [12] resulted in formation of
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SYNTHETIC TRANSFORMATIONS OF HIGHER TERPENOIDS: XVI.
69
Scheme 3.
O
O
O
O
Me
Me
HCOOH, dioxane
CH2
O
IIIa–IIId
Me
Me
O
Me COOMe
Me COOMe
XXI
XX
develop procedures for the synthesis of N-substituted
pyrroles of the labdane series and their two-step
transformation into decahydronaphtho[1,2-g]indole
derivatives.
a mixture of products. Compound XXI was obtained in
65% yield by treatment of stereoisomeric 2,5-dimeth-
oxydihydrofurans IIIa–IIId with 10% formic acid in
dioxane (Scheme 3).
The structure of the newly synthesized compounds
was determined on the basis of spectral data. Terpenoid
pyrroles V–XI and XIV–XVI characteristically showed
in the 1H NMR spectra signals from protons in the pyr-
role ring at δ 5.95 (14-H), 6.36 (16-H), and 6.46 ppm
(15-H) (for compound V). The 12-H protons resonated
in a weaker field (δ 2.35 and 2.63 ppm) than in the
spectrum of II [7]. The formation of the naphtho-
[1,2-g]indole system (compounds XII, XIII, XVII–
XIX) is confirmed by an appreciable upfield shift of
signals from the bridgehead carbon atoms (C5a and
C9a) in the 13C NMR spectra (ΔδC ≈ 5–9 ppm). The
9b-H and 11-H signals in the 1H NMR spectra of these
compounds are displaced downfield relative to the cor-
responding signals from 9-H and 12-H in the labdane
fragment of the initial ketones. The 1-H and 2-H
signals appear as doublets at δ 5.83 and 6.42 ppm,
respectively (J = 2.7 Hz), and the 4-H proton gives
a multiplet at δ 5.88 ppm.
EXPERIMENTAL
The mass spectra (electron impact, 70 eV) were re-
corded on a Finnigan MAT-8200 high-resolution mass
spectrometer (vaporizer temperature 190–250°C). The
1H and 13C NMR spectra were measured on Bruker
1
13
AC-200 (200.13 MHz for H and 50.32 MHz for C)
and Bruker DRX-500 instruments (500.13 MHz for
13
1H and 125.76 MHz for C) from solutions in CDCl3,
CD3OD, or CCl4. Signals in the NMR spectra were
assigned using various proton–proton, carbon–proton
and carbon–carbon (XXI) shift correlation techniques
(COSY, COLOC, and INADEQUATE). The UV spec-
tra were obtained on an HP 8453 UV-Vis spectro-
photometer from solutions in ethanol (c = 10–4 M). The
optical rotations ([α]D20, deg ml g–1 dm–1, c, g/100 ml)
were determined using a Polamat A polarimeter (Carl
Zeiss, λ 578 nm). The progress of reactions was moni-
tored by TLC on Silufol UV-254 plates. The products
were isolated by column chromatography on KSK
silica gel or aluminum oxide.
The UV spectra of decahydronaphtho[1,2-g]indoles
XII, XIII, and XVII–XIX contained absorption max-
ima at λ 265, 273, and 288 nm, indicating the presence
of a vinylpyrrole fragment. The structure of the buten-
olide moiety in molecule XXI was determined on the
Methyl (1′R,4R,4a′R,5′S,8a′R)-1′-[2-(2,5-dimeth-
oxy-2,5-dihydrofuran-3-yl)ethyl]-2,2,5′,8a′-tetra-
methyloctahydro-1′H-spiro[[1,3]dioxolane-4,2′-
naphthalene]-5′-carboxylate IIIa–IIId. A solution of
4.5 g (11.1 mmol) of dioxolane II and 1.5 ml of acetic
acid in 30 ml of methanol was cooled below 10°C, and
2.4 g (11.3 mmol) of N-chlorobenzenesulfonamide
sodium salt was added in portions under stirring. The
mixture was stirred for 30 min (TLC), treated with
50 ml of a 3% sodium sulfite solution to decompose
excess N-chloro amine, and extracted with diethyl
ether. The extract was washed with a 3% solution of
sodium hydroxide (2×15 ml) to remove PhSO2NH2
and with water and evaporated, and the residue was
13
basis of the INADEQUATE C–13C correlation spec-
trum. The C13 atom displayed three coupling constants
with C16, C14, and C12 (J = 61.7, 67.6, and 46.8 Hz,
respectively). Two coupling constants were observed
for C14, one with C13 (J = 67.6 Hz), and the other with
C15 (J = 38.2 Hz). The C15 nucleus was coupled with
C14 (J = 38.2 Hz), and C16 with C13 (J = 61.7 Hz).
These values were consistent with the corresponding
coupling constants of 3-substituted furan-2(5H)-ones
[13] in support of the assumed structure of XXI.
Thus the application of the Clauson-Kaas method to
a natural labdanoid, lambertianic acid, allowed us to
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CHERNOV et al.
70
subjected to chromatography on silica gel using petro-
leum ether–ethyl acetate (2:1) as eluent to isolate 4.9 g
(95%) of a mixture of stereoisomers IIIa–IIId as
5′-carboxylate (V). Dimethoxytetrahydrofuran mix-
ture IVa–IVd, 1.8 g (3.86 mmol), was dissolved in
15 ml of acetic acid, 3 ml of water and 3.0 ml of
25% aqueous methylamine were added, and the mix-
ture was heated for 10 min at 80–85°C, cooled with
water, and extracted with diethyl ether (3×20 ml). The
extract was washed with a 5% solution of ammonia
and evaporated, and the residue was subjected to
chromatography on silica gel using petroleum ether–
diethyl ether (2:1) as eluent. Yield 1.21 g (75%), oily
1
a colorless oily substance. H NMR spectrum (CCl4),
δ, ppm (J, Hz): 0.48 s and 0.51 s (3H, C20H3); 0.85–
0.92 m (2H, 1-H, 3-H); 0.96–1.02 m (1H, 5-H); 1.12 m
(1H, 2-H); 1.13 s and 1.14 s (3H, C19H3); 1.22–1.40 m
(2H, 7-H, 9-H); 1.21 s and 1.31 s [3H each, (CH3)2C];
1.45–1.57 m (2H, 2-H, 11-H); 1.62–1.75 m (3H, 1-H,
6-H, 11-H); 1.80–1.92 m (1H, 6-H); 2.00 m (1H, 7-H);
2.10 m (1H, 3-H); 2.16–2.40 m (2H, 12-H); 3.23 s,
3.24 s, 3.25 s, 3.28 s (6H, OCH3); 3.54 d (1H, 17-H,
J = 8.4); 3.57 s (3H, OCH3); 3.68 d (1H, 17-H, J =
8.4); 5.26 br.s, 5.27 br.s, 5.38 br.s, and 5.37 br.s (1H,
16-H); 5.47 m, 5.50 m, 5.51 m, and 5.52 m (1H,
15-H); 5.58 m, 5.60 m, and 5.61 m (1H, 14-H). Mass
spectrum, m/z (Irel, %): 466 [M]+ (2), 451 (22), 376
(66), 327 (42), 267 (28), 127 (100), 111 (47), 95
(25), 85 (27), 81 (33), 69 (36), 43 (42). Found: [M]+
466.28815. C26H42O7. Calculated: M 466.29303.
substance, [α]D20 = +2° (c = 5.9, chloroform). H NMR
1
spectrum (CDCl3), δ, ppm (J, Hz): 0.47 s (3H, C20H3),
1.01 d.t (1H, 3-H, J = 13.5, 4.3), 1.09 d.d.d (1H, 1-H,
J = 13.5, 4.0. 2.3), 1.14 d.d (1H, 5-H, J = 12.6, 2.8),
1.18 s (3H, C19H3), 1.30 d.d (1H, 9-H, J = 12.7, 3.4),
1.38 s and 1.43 s (6H, CH3), 1.35–1.48 m (2H, 2-H,
7-H), 1.60–1.72 m (2H, 2-H, 11-H), 1.78 m (3H, 1-H,
6-H, 11-H), 1.90 d.d.d (1H, 6-H, J = 12.8, 11.6, 3.6),
2.10 d.t (1H, 7-H, J = 12.8, 4.0), 2.15 m (1H, 3-H,
2J = 13.5), 2.35 d.d.d (1H, 12-H, J = 13.6, 13.0, 4.8),
2.63 d.d.d (1H, 12-H, J = 13.5, 12.9, 5.6), 3.57 s (3H,
CH3N), 3.61 s (3H, CH3O), 3.67 d.d (1H, 17-H, J =
8.4, 1.8), 3.77 d (1H, 17-H, J = 8.4), 5.95 d.d.d (1H,
14-H, J = 2.4, 2.1, 1.4), 6.36 d (1H, 16-H, J = 2.1),
6.46 m (1H, 15-H). 13C NMR spectrum, δC, ppm:
12.31 (C20), 18.95 (C2), 21.92 (C6), 26.78 (CH3), 28.42
(C11), 28.59 (CH3), 30.56 (C12), 35.78 (CH3N), 37.71
(C3), 38.76 (C1), 39.44 (C10), 39.52 (C7), 43.61 (C4),
51.08 (OCH3), 55.75 (C9), 56.51 (C5), 68.39 (C17),
85.03 (C8), 106.67 (C2′), 107.83 (C14), 118.59 (C15),
121.22 (C16), 125.13 (C13), 177.38 (C18). Mass spec-
trum, m/z (Irel, %): 417 [M]+ (22), 326 (28), 121 (44),
109 (100). Found: [M]+ 417.27669. C25H39NO4. Cal-
culated: M 417.27645.
Methyl (1′R,4R,4a′R,5′S,8a′R)-1′-[2-(2,5-dimeth-
oxy-2,5-tetrahydrofuran-3-yl)ethyl]-2,2,5′,8a′-tetra-
methyloctahydro-1′H-spiro[[1,3]dioxolane-4,2′-
naphthalene]-5′-carboxylates IVa–IVd. A solution of
4.66 g (10 mmol) of stereoisomer mixture IIIa–IIId in
30 ml of methanol was hydrogenated over Raney
nickel (prepared from 5.0 g of 20% Ni–Al alloy) under
atmospheric pressure. When the reaction was complete
(3–4 h, TLC), the catalyst was filtered off, and the
solvent was removed to obtain 4.6 g (98%) of stereo-
isomeric compounds IVa–IVd as an oily material.
1H NMR spectrum (CCl4), δ, ppm (J, Hz): 0.50 s and
0.52 s (3H, C20H3); 0.88–1.08 m (3H, 1-H, 3-H, 5-H);
1.06–1.12 m (2H, 2-H, 9-H); 1.15 s and 1.17 s (3H,
C19H3); 1.25–1.40 m (2H, 7-H, 9-H); 1.20 s and 1.35 s
[3H each, (CH3)2C]; 1.50–1.57 m (2H, 2-H, 11-H);
1.62–1.78 m (3H, 1-H, 6-H, 11-H); 1.86–1.99 m (2H,
6-H, 7-H); 2.10 m (1H, 3-H); 2.26–2.48 m (2H, 12-H);
3.24 s, 3.26 s, 3.29 s, and 3.38 s (6H, OCH3); 3.30 m
(1H, 13-H); 3.56 d (1H, 17-H, J = 8.4); 3.60 s (3H,
OCH3); 3.72 d (1H, 17-H, J = 8.4); 5.28 br.s, 5.32 br.s,
5.40 br.s, and 5.42 br.s (1H, 16-H); 5.48 m, 5.50 m,
5.51 m, and 5.55 m (1H, 15-H); 5.58 m, 5.62 m, and
5.64 m (1H, 14-H). Mass spectrum, m/z (Irel, %): 468
[M]+ (2), 453 (36), 390 (19), 376 (20), 347 (30), 329
(65), 287 (21), 269 (42), 135 (26), 127 (100), 109 (30),
107 (28). Found: [M]+ 468.30842. C26H44O7. Calculat-
ed: M 468.30868.
Methyl (1′R,4R,4a′R,5′S,8a′R)-1′-[2-(1-ethyl-1H-
pyrrol-3-yl)ethyl]-2,2,5′,8a′-tetramethyloctahydro-
1′H-spiro[1,3-dioxolane-4,2′-naphthalene]-5′-car-
boxylate (VI). Stereoisomeric dimethoxytetrahydro-
furan mixture IVa–IVd, 0.47 g (1 mmol), was dis-
solved in 10 ml of acetic acid, 2 ml of water and
0.5 ml of 50% aqueous ethylamine were added, and
the mixture was heated for 20 min at 80–85°C, diluted
with water, and extracted with diethyl ether. The ex-
tract was washed with a 5% solution of ammonia and
evaporated, and the residue was subjected to chroma-
tography on silica gel using petroleum ether–diethyl
ether (2:1) as eluent. Yield 0.36 g (84%), oily sub-
stance, [α]D20 = +20° (c = 4.8, chloroform). H NMR
1
Methyl (1′R,4R,4a′R,5′S,8a′R)-2,2,5′,8a′-tetra-
methyl-1′-[2-(1-methyl-1H-pyrrol-3-yl)ethyl]octa-
hydro-1′H-spiro[1,3-dioxolane-4,2′-naphthalene]-
spectrum (CDCl3), δ, ppm (J, Hz): 0.44 s (3H, C20H3),
0.90–1.10 m (3H, 1-H, 3-H, 5-H), 1.13 s (3H, C19H3),
1.18 t (3H, CH3, J = 7.0), 1.28 s and 1.37 s (6H, CH3),
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SYNTHETIC TRANSFORMATIONS OF HIGHER TERPENOIDS: XVI.
71
1.40–1.80 m (4H, 2-H, 6-H, 7-H, 9-H), 1.80–1.95 m
(3H, 2-H, 6-H, 11-H), 2.01 m (1H, 7-H), 2.09 m (1H,
11-H), 2.16–2.40 m (3H, 1-H, 3-H, 12-H), 2.50 m (1H,
12-H), 3.56 s (3H, OCH3), 3.58 d (1H, 17-H, J = 8.5),
3.68 d (1H, 17-H, J = 8.5), 3.80 q (2H, CH2), 5.72 d.d
(1H, 14-H, J = 2.5, 2.0), 6.20 d.d (1H, 16-H, J = 2.5,
2.0), 6.30 m (1H, 15-H). 13C NMR spectrum, δC, ppm:
12.51 (C20), 16.67 (CH3), 19.17 (C2), 22.14 (C6), 26.98
(CH3), 28.24 (C12), 28.77 (CH3), 30.78 (C11), 37.99
(C7), 38.95 (C3), 39.56 (C10), 39.71 (C1), 43.73 (C4),
43.84 (CH2), 51.03 (OCH3), 56.05 (C9), 56.65 (C5),
68.45 (CH2), 69.81 (C17), 85.01 (C8), 106.70 (C2′),
108.03 (C14), 116.79 (C15), 119.35 (C16), 124.94 (C13),
176.92 (C18). Mass spectrum, m/z (Irel, %): 431 [M]+
(15), 121 (53), 109 (100). Found: [M]+ 431.30368.
C26H41NO4. Calculated: M 431.30354.
diethyl ether, the extract was washed with a 5% solu-
tion of ammonia and evaporated, and the residue was
subjected to chromatography on aluminum oxide using
methanol–diethyl ether (1:1) as eluent. Yield 0.19 g
(70%), oily substance, [α]D20 = +15 (c = 2.9, chloro-
1
form). H NMR spectrum (CD3OD), δ, ppm (J, Hz):
0.58 s (3H, C20H3), 0.98–1.08 m (2H, 1-H, 3-H),
1.12 d.d (1H, 5-H, J = 12.2, 2.8), 1.16 s (3H, C19H3),
1.17 t (3H, CH3, J = 7.0), 1.32–1.48 m (3H, 2-H, 6-H,
9-H), 1.76–1.95 m (4H, 1-H, 2-H, 6-H, 11-H), 2.10 m
(1H, 7-H), 2.16 m (1H, 3-H), 2.28 m (1H, 11-H),
2.38 m (1H, 12-H), 2.52 m (1H, 12-H), 3.38 d (1H,
17-H, J = 8.2), 3.49 d (1H, 17-H, J = 8.2), 3.61 s (3H,
OCH3), 3.82 q (2H, CH2, J = 7.0), 5.80 m (1H, 14-H),
6.42 d.d (1H, 16-H, J = 2.6, 2.0), 6.50 m (1H, 15-H).
13C NMR spectrum, δC, ppm: 13.24 (C20H3), 14.75
(CH3), 16.41 (C2), 21.80 (C6), 27.60 (C11), 28.59 (C19),
31.09 (C12), 37.61 (C3), 38.08 (C1), 39.66 (C7), 40.25
(C10), 43.94 (C4), 50.89 (OCH3), 57.09 (C5), 60.27
(C9), 62.54 (CH2N), 64.03 (C17), 75.39 (C8), 107.74
(C14), 117.29 (C15), 119.73 (C16), 125.04 (C13), 178.51
(C18). Mass spectrum, m/z (Irel, %): 391 [M]+ (22), 459
(4), 346 (3), 254 (12), 173 (100), 160 (59). Found:
[M]+ 391.32104. C23H37NO4. Calculated: M 391.31444.
Methyl (1S,4aS,5R,6R,8aS)-6-hydroxy-6-hy-
droxymethyl-1,4a-dimethyl-5-[2-(1-methyl-1H-pyr-
rol-3-yl)ethyl]decahydronaphthalene-1-carboxylate
(VII). Water, 3 ml, was added to a solution of 0.9 g
(2.18 mmol) of pyrrole V in 15 ml of acetic acid, and
the mixture was heated for 2 h at 80–85°C and ex-
tracted with diethyl ether. The extract was washed with
a 5% solution of ammonia and evaporated, and the
residue was purified by chromatography on aluminum
oxide using methanol–diethyl ether (1:1) as eluent.
Yield 0.61 g (75%), mp 61–63°C, [α]D20 = +13° (c =
Methyl (1S,4aS,5R,6R,8aS)-5-[2-(1-benzyl-1H-
pyrrol-3-yl)ethyl]-6-hydroxy-6-hydroxymethyl-
1,4a-dimethyldecahydronaphthalene-1-carboxylate
(IX). A mixture of 1.2 g (2.6 mmol) of stereoisomeric
dimethoxytetrahydrofurans IVa–IVd and 0.5 ml of
benzylamine in 15 ml of 80% acetic acid was heated
for 3 h at 80–85°C, and the mixture was then treated as
described above for compound VII to isolate 0.81 g
(69%) of diol IX as an oily substance, [α]D20 = +10°
1
2.4, chloroform). H NMR spectrum (CDCl3–CCl4), δ,
ppm (J, Hz): 0.51 s (3H, C20H3), 0.98–1.05 (3H, 1-H,
3-H, 5-H), 1.15 s (3H, C19H3), 1.10–1.45 m (4H, 2-H,
6-H, 9-H, 11-H), 1.65–1.82 m (5H, 1-H, 2-H, 6-H,
7-H, 11-H), 2.08–2.18 m (1H, 7-H), 2.35 m (1H, 12-H),
2.50 m (1H, 3-H), 2.80 m (1H, 12-H), 3.40 d (1H,
17-H, J = 8.4), 3.48 s (3H, NCH3), 3.51 d (1H, 17-H,
J = 8.4), 3.55 s (3H, OCH3), 5.78 m (1H, 14-H),
6.25 br.s (1H, 16-H), 6.30 d.d (1H, 15-H, J = 2.2, 1.8).
13C NMR spectrum, δC, ppm: 13.21 (C20), 19.03 (C2),
21.41 (C6), 26.80 (C11), 28.53 (C19), 30.40 (C12), 35.53
(CH3N), 37.46 (C3), 37.80 (C1) 39.17 (C10), 39.63 (C7),
43.47 (C4), 50.76 (CH3O), 56.51 (C9), 59.12 (C5),
62.19 (C17), 74.54 (C8), 108.43 (C14), 118.64 (C15),
120.79 (C16), 124.67 (C13), 176.35 (C18). Mass spec-
trum, m/z (Irel, %) (EI): 377 [M]+ (23), 346 (16), 107
(100), 95 (85). Found: [M]+ 377.25666. C22H35NO4.
Calculated: M 377.25659.
1
(c = 3.7, chloroform). H NMR spectrum (CD3OD), δ,
ppm (J, Hz): 0.51 s (3H, C20H3), 0.98–1.05 (3H, 1-H,
3-H, 5-H), 1.15 s (3H, C19H3), 1.18–1.45 m (5H, 2-H,
6-H, 7-H, 9-H, 11-H), 1.65–1.92 m (3H, 2-H, 6-H,
11-H), 2.08–2.28 m (2H, 1-H, 7-H), 2.35 m (1H, 3-H),
2.50 m (1H, 12-H), 2.80 m (1H, 12-H), 3.40 d (1H,
17-H, J = 8.4), 3.68 d (1H, 17-H, J = 8.4), 3.65 s (3H,
OCH3), 4.88 s (2H, CH2), 5.88 d.d (1H, 14-H, J = 2.2,
1.8), 6.35 br.s (1H, 16-H, J = 1.8), 6.52 d (1H, 15-H,
13
J = 2.2), 7.11 m (2H, Ph), 7.30 m (3H, Ph). C NMR
spectrum, δC, ppm: 13.21 (C20H3), 19.83 (C2), 21.45
(C6), 28.80 (C11), 29.20 (C19H3), 29.58 (C12), 38.46
(C3), 38.92 (C1), 39.43 (C10), 40.63 (C7), 43.47 (C4),
50.76 (OCH3), 53.86 (CH2), 56.51 (C9), 60.12 (C5),
65.19 (C17), 74.54 (C8), 108.43 (C14), 118.64 (C15),
120.79 (C16), 125.67 (C13), 127.97 (C2′, C6′), 128.48
(C4′), 130.04 (C3′, C5′), 139.97 (C1′), 176.85 (C18). Mass
spectrum, m/z (Irel, %): 453 [M]+ (24), 422 (15),
Methyl (1S,4aS,5R,6R,8aS)-5-[2-(1-ethyl-1H-pyr-
rol-3-yl)ethyl]-6-hydroxy-6-hydroxymethyl-1,4a-di-
methyldecahydronaphthalene-1-carboxylate (VIII).
A solution of 0.3 g of pyrrole VI in 5 ml of acetic acid
and 1 ml of water was heated for 2 h at 80–85°C. The
mixture was diluted with water and extracted with
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 1 2008

CHERNOV et al.
72
345 (14), 183 (100), 170 (51), 91 (88). Found:
ppm: 12.38 (C20), 19.72 (C2), 21.69 (C6), 27.52 (C11),
28.59 (C19), 29.92 (C12), 38.04 (C3), 38.49 (C7), 39.00
(C1), 40.08 (C10), 43.98 (C4), 50.71 (OCH3), 57.22
(C9), 60.64 (C5), 65.02 (C17), 76.23 (C8), 109.46 (C14),
116.91 (C4′), 119.08 (C15), 122.03 (C16), 125.88 (C13),
128.67, 128.97 (C3′, C5′), 130.22 (C2′, C6′), 141.57
(C1′), 179.20 (C18). Mass spectrum, m/z (Irel, %): 439
[M]+ (16), 408 (9), 169 (100), 109 (28). Found:
[M]+ 439.27253. C27H37NO4. Calculated: M 439.27224.
[M]+ 453.28717. C28H39NO4. Calculated: M 453.28789.
Methyl (1S,4aS,5R,6R,8aS)-5-[2-(1-allyl-1H-pyr-
rol-3-yl)ethyl]-6-hydroxy-6-hydroxymethyl-1,4a-
dimethyldecahydronaphthalene-1-carboxylate (X).
Following a similar procedure, from 0.65 g (1.4 mmol)
of stereoisomeric dimethoxytetrahydrofurans IVa–IVd
and 0.5 ml of allylamine in 10 ml of 80% acetic acid
we obtained 0.35 g (62%) of diol X as an oily sub-
stance, [α]D20 = +18° (c = 1.8, chloroform). H NMR
1
Methyl (6S,5aR,9aR)-3,6,9a-trimethyl-5,5a,6,7,-
8,9,9a,9b,10,11-decahydro-3H-naphtho[1,2-g]in-
dole-6-carboxylate (XII). A solution of 0.22 g
(1.03 mmol) of sodium periodate in 2 ml of water was
added dropwise to a solution of 0.38 g of diol VII in
8 ml of methanol containing 0.5 ml of acetic acid. The
mixture was stirred for 3 min, diluted with water,
treated with aqueous ammonia until alkaline reaction,
and extracted with diethyl ether. The extract was evap-
orated, and the residue was subjected to chromatog-
raphy on silica gel using petroleum ether–diethyl ether
(1:1) as eluent. Yield 0.21 g (46%), mp 138–140°C
(from petroleum ether–diethyl ether), [α]D20 = +52° (c =
1.3, chloroform). UV spectrum, λmax, nm (logε): 203
spectrum (CD3OD), δ, ppm (J, Hz): 0.60 s (3H,
C20H3), 0.92 d.t (1H, 1-H, J = 13.3, 4.3), 0.96 d.d.d
(1H, 3-H, J = 13.2, 12.8, 4.2), 1.12 s (3H, C19H3),
1.14 d.d (1H, 5-H, J = 12.7, 2.9), 1.40 d.d (1H, 9-H,
J = 11.2, 3.0), 1.43–1.51 m (3H, 2-H, 7-H, 11-H),
1.66–1.80 m (4H, 1-H, 2-H, 6-H, 11-H), 1.90 m (1H,
6-H), 2.12 m (1H, 7-H, 2J = 12.8), 2.18 d.d.d (1H, 3-H,
J = 13.2, 4.0, 2.6), 2.38 m (1H, 12-H), 2.65 m (1H,
12-H), 3.54 d (1H, 17-H, J = 8.1), 3.62 s (3H, OCH3),
3.77 d (1H, 17-H, J = 8.1), 4.50 m (2H, C1′H2), 5.14 m
(2H, C3′H2), 5.90 m (1H, 14-H), 6.01 m (1H, 2′-H),
6.45 d (1H, 16-H, J = 2.0), 6.54 m (1H, 15-H).
13C NMR spectrum, δC, ppm: 14.14 (C20H3), 19.57
(C2), 22.67 (C6), 28.39 (C11), 29.12 (C19H3), 30.88
(C12), 38.56 (C3), 38.97 (C1) 40.51 (C10), 41.15 (C7),
45.00 (C4), 51.68 (OCH3), 52.62 (C1′), 57.97 (C9),
61.11 (C5), 64.88 (C17), 76.17 (C8), 109.04 (C14),
116.82 (C3′), 118.91 (C15), 121.35 (C16), 126.16 (C13),
136.97 (C2′), 179.21 (C18). Mass spectrum, m/z
(Irel, %): 403 [M]+ (15), 133 (100), 121 (96), 109 (27),
81 (30). Found: [M]+ 403.27220. C24H37NO4. Calculat-
ed: M 403.27224.
1
(4.22), 265 (4.64), 273 (4.93), 288 (4.13). H NMR
spectrum (CDCl3), δ, ppm (J, Hz): 0.68 s (3H, C14H3),
1.05–1.12 m (2H, 7-H, 9-H), 1.22 s (3H, C13H3),
1.37 q.d (1H, 10-H, J = 12.5, 4.9), 1.46 d.d (1H, 5a-H,
J = 12.2, 4.8), 1.51 m (1H, 8-H), 1.90–2.00 m (4H,
8-H, 9-H, 9b-H, 10-H), 2.17 d.d.d (1H, 7-H, J = 13.5,
3.2, 1.7), 2.40 d.d.d.d (1H, 5-H, J = 18.6, 5.8, 2.6, 2.2),
2.49 d.d.d (1H, 11-H, J = 15.5, 12.5, 4.5), 2.56 d.d.t
(1H, 5-H, J = 18.6, 12.2, 2.4, 4.8), 2.65 d.d.d.d (1H,
11-H, J = 15.5, 4.9, 2.3), 3.67 s (3H, CH3N), 3.71 s
(3H, CH3O), 5.83 d (1H, 1-H, J = 2.7), 5.88 d.d (1H,
4-H, J = 6.0, 2.5), 6.42 d (1H, 2-H, J = 2.7). 13C NMR
spectrum, δC, ppm: 12.90 (C14), 19.62 (C8), 24.21
(C11), 24.58 (C10), 24.59 (C5), 28.83 (C13), 35.57 (C9a),
37.91 (C1′), 38.06 (C7), 39.63 (C9), 43.70 (C6), 50.74
(C5a), 51.20 (CH3O), 51.53 (C9b), 105.22 (C1), 114.48
(C4), 121.52 (C11a), 124.49 (C2), 127.77 (C3a), 128.76
(C3b), 177.62 (C12). Mass spectrum, m/z (Irel, %):
327 [M]+ (100), 252 (44), 147 (71). Found:
[M]+ 327.21998. C21H29NO2. Calculated: M 327.21982.
Methyl (1S,4aS,5R,6R,8aS)-6-hydroxy-6-hy-
droxymethyl-1,4a-dimethyl-5-[2-(1-phenyl-1H-pyr-
rol-3-yl)ethyl]decahydronaphthalene-1-carboxylate
(XI) was synthesized in a similar way from 0.8 g
(1.7 mmol) of stereoisomer mixture IVa–IVd and
0.5 ml of aniline in 10 ml of 80% acetic acid. Yield
0.38 g (51%), oily substance, [α]D20 = +9° (c = 3.9,
1
chloroform). H NMR spectrum (CD3OD), δ, ppm
(J, Hz): 0.63 s (3H, C20H3), 0.90 d.t (1H, 1-H, J = 13.3,
4.3), 0.96 d.d.d (1H, 3-H, J = 13.2, 12.8, 4.2), 1.09 s
(3H, C19H3), 1.16 d.d (1H, 5-H, J = 12.6, 2.9), 1.40 m
(1H, 2-H), 1.47 m (1H, 11-H), 1.53 d.d (1H, 9-H, J =
11.1, 3.2), 1.72–1.88 m (4H, 1-H, 2-H, 6-H, 11-H),
Methyl (6S,5aR,9aR)-3-ethyl-6,9a-dimethyl-
5,5a,6,7,8,9,9a,9b,10,11-decahydro-3H-naphtho-
[1,2-g]indole-6-carboxylate (XIII). A solution of
0.11 g (0.51 mmol) of sodium periodate in 2 ml of
water was added dropwise to a solution of 0.2 g
(0.45 mmol) of diol VIII in 5 ml of methanol contain-
ing 0.3 ml of acetic acid. The mixture was stirred for
5 min, diluted with water, treated with a 5% solution of
2
1.90 m (2H, 6-H, 7-H), 2.19 m (1H, 3-H, J = 13.2),
2.29 d.d.d (1H, 7-H, J = 12.7, 4.0, 2.6), 2.44 m (1H,
12-H), 2.63 m (1H, 12-H), 3.44 d (1H, 17-H, J = 8.1),
3.50 s (3H, OCH3), 3.62 d (1H, 17-H, J = 8.1), 5.94 m
(1H, 14-H), 6.45 d (1H, 16-H, J = 2.0), 6.54 m (1H,
13
15-H), 7.26–7.50 m (5H, Ph). C NMR spectrum, δC,
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SYNTHETIC TRANSFORMATIONS OF HIGHER TERPENOIDS: XVI.
73
ammonia to alkaline reaction, and extracted with di-
ethyl ether. The extracts were washed with water and
evaporated, and the residue was purified by chroma-
tography on silica gel using petroleum ether–diethyl
ether (1:1) as eluent. Yield 0.09 g (51%), mp 121–
123°C (from petroleum ether), [α]D20 = +47° (c = 2.1,
Found: [M]+ 421.26151. C27H35NO3. Calculated:
M 421.26168.
Methyl (1S,4aS,5R,8aS)-5-[2-(1-allyl-1H-pyrrol-
3-yl)ethyl]-1,4a-dimethyl-6-oxodecahydronaph-
thalene-1-carboxylate (XV). A solution of 0.11 g
(0.51 mmol) of sodium periodate in 2 ml of water was
added to a solution of 0.2 g (0.5 mmol) of diol X in
5 ml of methanol. After 10 min, the mixture was diluted
with water and extracted with diethyl ether. The extract
was evaporated, and the residue was subjected to
chromatography on aluminum oxide using diethyl
ether as eluent to isolate 0.14 g (76%) of ketone XV as
an oily substance, [α]D20 = +19° (c = 5.0, chloroform).
1H NMR spectrum (CD3OD), δ, ppm (J, Hz): 0.55 s
(3H, C20H3), 1.12 d.t (1H, 3-H, J = 13.2, 4.2), 1.21 m
(2H, 1-H, 5-H), 1.28 s (3H, C19H3), 1.45–1.55 m (3H,
2-H, 7-H, 11-H), 1.68–1.90 m (4H, 2-H, 6-H, 9-H,
11-H), 1.98 m (2H, 1-H, 6-H), 2.08–2.28 m (2H, 3-H,
7-H), 2.32–2.46 m (1H, 12-H), 2.45–2.52 m (1H,
12-H), 3.62 s (3H, OCH3), 4.45 m (2H, 1′-H), 5.11 m
(2H, 3′-H), 5.89 d.d (1H, 14-H, J = 2.5, 2.1), 6.01 m
(1H, 2′-H), 6.40 d (1H, 16-H, J = 2.1), 6.56 d (1H,
15-H, J = 2.5). 13C NMR spectrum, δC, ppm: 13.77
(C20), 20.85 (C2), 24.54 (C6), 27.04 and 27.20 (C11,
C12), 29.12 (C19), 38.98 (C3), 40.36 (C1), 44.05 (C10),
44.61 (C7), 45.51 (C4), 51.80 (OCH3), 52.66 (C1′),
55.85 (C5), 63.13 (C9), 109.13 (C14), 116.70 (C3′),
119.32 (C15), 121.64 (C16), 124.98 (C13), 136.69 (C2′),
178.71 (C18), 214.68 (C8).
1
chloroform). H NMR spectrum (CDCl3), δ, ppm
(J, Hz): 0.67 s (3H, C14H3), 1.11 m (2H, 7-H, 9-H),
1.19 s (3H, C13H3), 1.37 t (3H, C2′H3, J = 7.0), 1.39–
1.52 m (3H, 5a-H, 8-H, 10-H), 1.90–2.00 m (4H, 8-H,
9-H, 9b-H, 10-H), 2.15 m (1H, 7-H), 2.38–2.50 m (2H,
5-H, 11-H), 2.56–2.62 m (2H, 5-H, 11-H), 3.64 s (3H,
OCH3), 4.01 q (2H, C1′H2, J = 7.0), 5.69 m (1H, 4-H),
5.74 d (1H, 1-H, J = 2.1), 6.39 d (1H, 2-H, J = 2.0).
13C NMR spectrum, δC, ppm: 13.09 (C14), 16.53 (C2′),
19.82 (C8), 24.52 and 24.81 (C11, C10), 24.93 (C5),
29.01 (C13), 35.82 (C9a), 38.31 (C7), 39.89 (C9), 43.81
(C6), 43.83 (C1′), 51.00 (CH3O), 51.14 (C5a), 51.95
(C9b), 105.96 (C1), 113.85 (C4), 121.99 (C11a), 122.93
(C2), 126.87 (C3a), 128.83 (C3b), 177.11 (C12). Mass
spectrum, m/z (Irel, %): 341 [M]+ (100), 326 (25), 266
(36), 161 (70). Found: [M]+ 341.23551. C22H31NO2.
Calculated: M 341.22546.
Methyl (1S,4aS,5R,8aS)-5-[2-(1-benzyl-1H-pyr-
rol-3-yl)ethyl]-1,4a-dimethyl-6-oxodecahydronaph-
thalene-1-carboxylate (XIV). A solution of 0.24 g
(1.12 mmol) of sodium periodate in 3 ml of water was
added to a solution of 0.5 g (1.1 mmol) of diol IX in
10 ml of methanol. After 10 min, the mixture was
diluted with water and extracted with diethyl ether.
The extract was evaporated, and the residue was
subjected to chromatography on aluminum oxide using
diethyl ether as eluent. Yield 0.38 g (82%), oily sub-
Methyl (1S,4aS,5R,8aS)-1,4a-dimethyl-6-oxo-
5-[2-(1-phenylpyrrol-3-yl)ethyl]decahydronaph-
thalene-1-carboxylate (XVI). A solution of 0.12 g
(0.56 mmol) of sodium periodate in 2 ml of water was
added to a solution of 0.25 g (0.55 mmol) of diol XI
in 8 ml of methanol. After 10 min, the mixture was
diluted with water and extracted with diethyl ether.
The extract was evaporated, and the residue was sub-
jected to chromatography on aluminum oxide using
diethyl ether as eluent to isolate 0.20 g (83%) of
ketone XVI as an oily substance, [α]D20 = +8° (c = 2.2,
stance, [α]D20 = +14° (c = 4.4, chloroform). H NMR
1
spectrum (CDCl3), δ, ppm (J, Hz): 0.47 s (3H, C20H3),
0.88–0.96 m (2H, 1-H, 3-H), 1.08 d.d (1H, 5-H, J =
12.4, 2.6), 1.26 s (3H, C19H3), 1.45–1.55 m (3H, 2-H,
7-H, 11-H), 1.66–1.80 m (2H, 2-H, 6-H, 11-H), 1.92–
2.04 m (3H, 1-H, 6-H, 7-H), 2.20 m (1H, 3-H), 2.28–
2.36 m (1H, 12-H), 2.38–2.52 m (1H, 12-H), 3.55 s
(3H, OCH3), 4.91 s (2H, CH2), 5.79 d.d (1H, 14-H, J =
2.5, 2.1), 6.43 d (1H, 16-H, J = 2.1), 6.64 d (1H, 15-H,
1
chloroform). H NMR spectrum (CD3OD), δ, ppm
(J, Hz): 0.53 s (3H, C20H3), 0.91–1.02 m (2H, 1-H,
3-H), 1.08 d.d (1H, 5-H, J = 12.4, 2.6), 1.26 s (3H,
C19H3), 1.45–1.55 m (3H, 2-H, 6-H, 11-H), 1.66 m
(1H, 9-H, 11-H), 1.70–1.80 m (2H, 2-H, 7-H), 1.98–
2.04 m (1H, 6-H), 2.20 m (1H, 3-H), 2.30 m (3H, 1-H,
7-H, 12-H), 2.50 m (1H, 12-H), 3.62 s (3H, OCH3),
5.91 d.d (1H, 14-H, J = 2.5, 2.1), 6.43 d (1H, 16-H,
J = 2.1), 6.64 d (1H, 15-H, J = 2.5), 7.14 m (2H, Ph),
7.29 m (3H, Ph). 13C NMR spectrum, δC, ppm: 13.52
(C20), 20.46 (C2), 23.92 (C6), 26.36 and 26.99 (C11,
13
J = 2.5), 7.14 m (2H, Ph), 7.29 m (3H, Ph). C NMR
spectrum, δC, ppm: 13.79 (C20), 20.82 (C2), 24.37 (C6),
26.99 and 27.03 ((C11, C12), 29.14 (C19), 38.99 (C3),
40.32 (C1), 44.02 (C10), 44.54 (C7), 45.49 (C4), 51.80
(OCH3), 53.90 (C1′), 55.88 (C5), 62.85 (C9), 109.45
(C14), 119.73 (C15), 122.17 (C16), 125.27 (C13), 128.03
(C2′, C6′), 128.39 (C4′), 129.54 (C3′, C5′), 140.60 (C1′),
178.68 (C18), 213.26 (C8). Mass spectrum, m/z (Irel, %):
421 [M]+ (20), 362 (3), 183 (100), 171 (46), 90 (99).
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CHERNOV et al.
74
C12), 29.42 (C19), 38.57 (C3), 39.87 (C1), 43.53 (C10),
43.84 (C7), 44.88 (C4), 51.80 (OCH3), 55.10 (C5),
62.62 (C9), 111.80 (C14), 116.93 (C15), 119.35 (C16),
119.88 (C2′, C6′), 125.60 (C4′), 127.33 (C13), 130.41
(C3′, 5′), 141.64 (C1′), 178.60 (C18), 211.07 (C8).
5.16 m (1H, 3′-H), 5.70 m (1H, 4-H), 5.82 d (1H,
1-H, J = 2.8), 5.96 m (1H, 2′-H), 6.50 d (1H, 2-H, J =
13
2.8). C NMR spectrum, δC, ppm: 13.50 (C14), 20.80
(C8), 25.49 and 25.77 (C11, C10), 26.41 (C5), 29.67
(C13), 36.80 (C9a), 38.68 (C7), 40.14 (C9), 45.00 (C6),
51.65 (C5a), 52.09 (C9b), 52.75 (CH3O), 69.07 (C1′),
106.86 (C8), 115.05 (C4), 116.60 (C3′), 122.72 (C11a),
125.27 (C2), 128.56 (C3a), 129.48 (C3b), 136.73 (C2′),
179.26 (C12).
Methyl (6S,5aR,9aR)-3-benzyl-6,9a-dimethyl-
5,5a,6,7,8,9,9a,9b,10,11-decahydro-3H-naphtho-
[1,2-g]indole-6-carboxylate (XVII). A solution of
0.2 g (0.48 mmol) of ketone XIV and 1 ml of acetic
acid in 8 ml of methanol was kept for 2 h at room tem-
perature. It was then diluted with water and extracted
with diethyl ether. The extract was washed with a 5%
solution of ammonia and evaporated, and the residue
was subjected to chromatography on silica gel using
petroleum ether–diethyl ether as eluent (2:1). Yield
Methyl (6S,5aR,9aR)-6,9a-dimethyl-3-phenyl-
5,5a,6,7,8,9,9a,9b,10,11-decahydro-3H-naphtho-
[1,2-g]indole-6-carboxylate (XIX). A solution of
0.2 g (0.49 mmol) of ketone XVI and 0.2 ml of acetic
acid in 8 ml of methanol was kept for 2 h, diluted with
water, and extracted with diethyl ether. The extract was
washed with a 5% solution of ammonia, the solvent
was removed, and the residue was subjected to chro-
matography on silica gel using petroleum ether–diethyl
ether (2:1) as eluent. Yield 0.14 g (75%), oily sub-
1
0.13 g (71%), oily substance. H NMR spectrum
(CD3OD), δ, ppm (J, Hz): 0.65 s (3H, C14H3), 0.88–
0.96 m (2H, 7-H, 9-H), 1.13 s (3H, C13H3), 1.11–
1.20 m (2H, 5a-H, 10-H), 1.30–1.52 m (3H, 8-H, 9b-H,
10-H), 1.90–2.01 m (2H, 8-H, 9-H), 2.11–2.25 m (3H,
5-H, 7-H, 11-H), 2.56 m (1H, 5-H), 2.68 d.d.d (1H,
11-H, J = 14.2, 6.2, 2.5), 3.62 s (3H, OCH3), 5.23 s
(2H, 1′-H), 5.56 m (1H, 4-H), 5.91 d (1H, 1-H, J =
1.8), 6.60 d (1H, 2-H, J = 1.8), 7.00 m (2H, Ph),
7.30 m (3H, Ph). 13C NMR spectrum, δC, ppm: 13.50
(C14), 20.61 (C8), 25.52 and 25.66 (C11, C10), 26.08
(C5), 29.23 (C13), 36.75 (C9a), 39.19 (C7), 40.79 (C9),
44.95 (C6), 51.75 (C5a), 51.97 (CH3O), 53.09 (C9b),
53.38 (C1′), 107.09 (C1), 115.72 (C4), 123.18 (C11a),
126.14 (C2), 126.64 (C2″, C6″), 127.83 (C4″), 128.83
(C3a), 129.32 (C3b), 129.57 (C3″, C5″), 140.62 (C1″),
179.29 (C12). Mass spectrum, m/z (Irel, %): 403
[M]+ (100), 328 (21), 223 (40), 91 (60). Found:
[M]+ 403.25132. C27H33NO2. Calculated: M 403.25111.
1
stance. H NMR spectrum (CD3OD), δ, ppm (J, Hz):
0.68 s (3H, C14H3), 0.82–1.16 m (3H, 7-H, 9-H, 10-H),
1.14 s (3H, C13H3), 1.30–1.54 m (2H, 5a-H, 8-H),
1.92–2.06 m (4H, 8-H, 9-H, 9b-H, 10-H), 2.11 m (1H,
7-H), 2.25–2.36 m (2H, 5-H, 11-H), 2.55 d.d.d (1H,
5-H, J = 14.2, 6.2, 2.5), 2.72 d.d.d (1H, 11-H, J = 18.2,
4.8, 2.5), 3.62 s (3H, OCH3), 4.98 m (1H, 4-H), 5.97 d
(1H, 1-H, J = 2.8), 6.56 d (1H, 2-H, J = 2.8), 7.28 m
(2H, Ph), 7.40 m (3H, Ph). 13C NMR spectrum, δC,
ppm: 13.50 (C14), 20.80 (C8), 25.32 and 25.66 (C10,
C11), 26.13 (C5), 29.18 (C13), 36.75 (C9a), 39.19 (C7),
40.73 (C9), 44.98 (C6), 51.64 (C5a), 51.97 (CH3O),
52.76 (C9b), 107.64 (C1), 115.05 (C4), 116.42 (C4′),
123.66 (C11a), 126.34 (C2), 128.14 and 128.19 (C3′, C5′),
128.39 (C3a), 129.18 (C3b), 130.17 (C2′, C6′), 143.99
(C1′), 179.26 (C12). Mass spectrum, m/z (Irel, %): 389
[M]+ (100), 374 (43), 312 (34), 209 (32). Found:
[M]+ 389.23521. C26H31NO2. Calculated: M 389.23546.
Methyl (6S,5aR,9aR)-3-allyl-6,9a-dimethyl-
5,5a,6,7,8,9,9a,9b,10,11-decahydro-3H-naphtho-
[1,2-g]indole-6-carboxylate (XVIII). A solution of
0.15 g (0.40 mmol) of ketone XV and 1 ml of acetic
acid in 8 ml of methanol was kept for 30 min, diluted
with water, and extracted with diethyl ether. The ex-
tract was washed with a 5% solution of ammonia, the
solvent was removed, and the residue was subjected to
chromatography using petroleum ether–diethyl ether
(2:1) as eluent. Yield 0.11 g (77%), oily substance.
1H NMR spectrum (CD3OD), δ, ppm (J, Hz): 0.70 s
(3H, C14H3), 0.88–0.96 m (2H, 7-H, 9-H), 1.15 m (1H,
10-H), 1.13 s (3H, C13H3), 1.21–1.38 m (2H, 5a-H,
8-H), 1.52 m (1H, 8-H), 1.90–2.01 m (3H, 9-H, 9b-H,
10-H), 2.19 m (1H, 7-H), 2.38–2.55 m (3H, 5-H,
11-H), 2.68 d.d.d (1H, 11-H, J = 14.2, 6.2, 2.5), 3.65 s
(3H, OCH3), 4.60 m (1H, 3′-H), 4.83 m (2H, 1′-H),
Methyl (1′R,4R,4a′R,5′S,8a′R)-2,2,5′,8a′-tetra-
methyl-1′-[2-(2-oxo-2,5-dihydrofuran-3-yl)ethyl]-
octahydro-1′H-spiro[1,3-dioxolane-4,2′-naphtha-
lene]-5′-carboxylate (XXI). Formic acid, 0.5 ml, was
added to a solution of 0.2 g (0.43 mmol) of stereo-
isomeric 2,5-dimethoxydihydrofuran mixture IIIa–
IIId in 5 ml of dioxane, and the mixture was kept for
2 h, diluted with water, and extracted with diethyl
ether. The extract was washed with a 5% solution of
ammonia and evaporated, and the residue was sub-
jected to chromatography on silica gel using petroleum
ether–diethyl ether (1:1) as eluent. Yield 0.11 g (65%),
mp 151–153°C (from petroleum ether–acetone).
1H NMR spectrum (CDCl3), δ, ppm (J, Hz): 0.41 s
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 1 2008

SYNTHETIC TRANSFORMATIONS OF HIGHER TERPENOIDS: XVI.
75
(3H, C20H3), 0.92 d.d (1H, 3-H, J = 13.3, 4.3, 2.1),
0.96 d.d (1H, 1-H, J = 14.4, 4.8, 2.6), 1.06 d.d (1H,
5-H, J = 12.6, 2.8), 1.10 s (3H, C19H3), 1.26 d.d
(1H, 9-H, J = 12.2, 3.0), 1.20 s and 1.30 s [3H each,
(CH3)2C], 1.40–1.50 m (3H, 2-H, 11-H), 1.62 d.d.d.d
(1H, 6-H, J = 14.6, 12.6, 3.8, 2.5), 1.66–1.75 m (3H,
1-H, 2-H, 7-H), 1.83 d.d.d (1H, 6-H, J = 14.6, 5.2,
2.8), 2.01 d.t (1H, 7-H, J = 12.8, 3.4), 2.07 d.d.d (1H,
3-H, J = 13.3, 4.6, 2.3), 2.17 m (1H, 12-H), 2.40 m
(1H, 12-H), 3.52 d.d (1H, 17-H, J = 8.5, 1.7), 3.55 s
(3H, OCH3), 3.67 d (1H, 17-H, J = 8.5), 4.66 d (2H,
3. Shults, E.E. and Tolstikov, G.A., Selected Methods for
Synthesis and Modification of Heterocycles, Kar-
tsev, V.G., Ed., 2006, vol. 4, p. 241.
4. Engler, T.A., Furness, K., Malhotra, S., Sanchez-Marti-
nez, C., Shih, C., Xie, W., Zhu, G., Zhou, X., Conner, S.,
Faul, M.M., Sullivan, K.A., Kolis, S.P., Brooks, H.B.,
Patel, B., Schultz, R.M., DeHahn, T.B., Kirmani, K.,
Spencer, C.D., Watkins, S.A., Considine, E.L., Demp-
sey, J.A., Ogg, C.A., Stamm, N.B., Anderson, B.D.,
Campbell, R.M., Vasudevan, V., and Lytle, M.L.,
Bioorg. Med. Chem. Lett., 2003, vol. 13, p. 2261.
5. Ylikoski, J., Pirvola, U., Saarma, M., Walton, K., and
Hudkins, R.L., World Patent Appl. no. WO 2000-
018407; Chem. Abstr., 2000, vol. 132, no. 260705.
13
15-H, J = 1.8), 7.02 d (1H, 14-H, J = 1.8). C NMR
spectrum, δC, ppm: 12.41 (C20), 18.96 (C2), 21.87 (C6),
23.36 (C11), 26.73 (C19), 28.38 (C12), 28.48 and 28.63
(CH3), 37.71 (C3), 38.83 (C1), 39.47 (C7), 39.54 (C10),
43.55 (C4), 51.01 (CH3), 55.79 (C5), 56.11 (C9), 68.26
(C17), 69.57 (C15), 84.71 (C8), 106.60 (C2′), 134.75
(C13), 143.23 (C14), 173.39 (C16), 176.70 (C18). Mass
spectrum, m/z (Irel, %): 420 [M]+ (34), 405 (57), 362
(51), 345 (34), 285 (100), 237 (26), 127 (98), 121 (28),
109 (27), 105 (31), 95 (26), 81 (32), 72 (40). Found:
[M]+ 420.25101. C24H36O6. Calculated: M 420.25117.
6. Router, S., Merour, J.-Y., Dia, N., Lansiaux, A., Bail-
ly, C., Lozach, O., and Meijer, L., J. Med. Chem., 2005,
vol. 49, p. 789.
7. Chernov, S.V., Shul’ts, E.E., Shakirov, M.M., and Tol-
stikov, G.A., Russ. J. Org. Chem., 2006, vol. 42, p. 36.
8. Fakstorp, J., Raleigh, D., and Schniepp, L.E., J. Am.
Chem. Soc., 1950, vol. 72, p. 869.
9. Asili, J., Lambert, M., Ziegler, H.L., Stark, D., Saira-
fianpour, M., Witt, M., Asghari, G., Ibrahimi, I.S., and
Jaroszewski, J.W., J. Nat. Prod., 2004, vol. 67, p. 631.
This study was performed under financial support
by the Russian Foundation for Basic Research (project
nos. 06-03-32150 and 05-03-32365) and by the Presi-
dent of the Russian Federation (program for support of
leading scientific schools, project no. NSh 1589.3-06).
10. Kim, K.A., Moon, T.C., Lee, S.W., Chung, K.C.,
Han, B.H., and Chang, H.W., Planta Medica, 1999,
vol. 65, p. 39.
11. Yang, H.O., Kang, Y.H., Suh, D.-Y., Kim, Y.C., and
Han, B.H., Planta Medica, 1995, vol. 61, p. 519.
12. Shults, E.E., Velder, J., Schmalz, H.-G., Chernov, S.V.,
Rubalova, T.V., Gatilov, Y.V., Henze, G., Tolsti-
kov, G.A., and Prokop, A., Bioorg. Med. Chem. Lett.,
2006, vol. 16, p. 4228.
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 44 No. 1 2008