Transformations of isocaryophyllene diepoxide under conditions of homogeneous and heterogeneous acid catalysis

Article abstract of DOI:10.1007/s11178-005-0335-3

Transformations of isocaryophyllene diepoxide (an isomer of widely spread natural sesquiterpene) were studied in various acidic media under conditions of homogeneous and heterogeneous catalysis. A number of previously unknown compounds were thus obtained. The experimental data were compared with the results of molecular-mechanics and quantum-chemical simulation of the most probable transformation paths.

Full text of DOI:10.1007/s11178-005-0335-3

Russian Journal of Organic Chemistry, Vol. 41, No. 9, 2005, pp. 1280–1285. Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 9, 2005,
pp. 1307–1312.
Original Russian Text Copyright © 2005 by Salomatina, Yarovaya, Korchagina, Gatilov, Polovinka, Barkhash.
Dedicated to Full Member of the Russian Academy of Sciences
N.S. Zefirov on His 70th Anniversary
Transformations of Isocaryophyllene Diepoxide under Conditions
of Homogeneous and Heterogeneous Acid Catalysis
1
2
2
2
O. V. Salomatina , O. I. Yarovaya , D. V. Korchagina , Yu. V. Gatilov ,
2
2
M. P. Polovinka , and V. A. Barkhash
1
Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090 Russia
e-mail: ana@nioch.nsc.ru
2
Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Division, Russian Academy of Sciences,
pr. Akademika Lavrent’eva 9, Novosibirsk, 630090 Russia
Received January 29, 2005
Abstract—Transformations of isocaryophyllene diepoxide (an isomer of widely spread natural sesquiterpene)
were studied in various acidic media under conditions of homogeneous and heterogeneous catalysis. A number
of previously unknown compounds were thus obtained. The experimental data were compared with the results
of molecular-mechanics and quantum-chemical simulation of the most probable transformation paths.
We previously studied acid-catalyzed transforma-
tions of diepoxy derivatives of caryophyllene (which is
one of the most widely spread natural sesquiterpenes)
over solid catalysts and under homogeneous conditions
barrier to interconversion between the conformers (as
in the case of initial diene I) [4] rules out conforma-
tionally controlled reaction. The stable conformers
were revealed using Dreiding models and molecular
dynamics calculations. The heats of formation of pos-
sible conformers were estimated in terms of the PM3
semiempirical method, and the most stable conformers
(within 5 kcal/mol) were calculated by the DFT
method (B3LYP/6 31G*). Scheme 1 shows the best
(within 2 kcal/mol) conformers according to the DFT
calculations.
[
1]. With a view to elucidate how the substrate struc-
ture affects the results of transformations, in the pres-
ent work we examined transformations of isomeric
isocaryophyllene diepoxide under conditions of homo-
geneous and heterogeneous catalysis. Isocaryophyllene
(
I) is the cis isomer of caryophyllene with respect to
the 4(5)-double bond; like caryophyllene, compound I
readily undergoes cyclization in the presence of acids;
however, the composition of the cyclization products
is different due to the lack of strain at the endocyclic
The synthesis of diepoxy derivative III and its
transformations in nucleophilic media were described
in [5]. It was shown that the 4,5-epoxy group is stable
in alkaline medium; therefore, the corresponding
8,13-diol is formed, and the latter undergoes intramo-
lecular cyclization to give tricyclic product (Scheme 1).
Acid-catalyzed transformations of diepoxide III were
not studied previously.
4
(5)-double bond [2, 3].
Treatment of diene I with a peroxy acid gives rise
to epimeric epoxy derivatives as a result of oxidation
of the 4(5)-double bond, 4β,5β- (II) and 4α,5α-epoxy-
isocariophyllenes. Compound II was isolated from the
reaction mixture by recrystallization from hexane; its
oxidation with monoperoxyphthalic acid afforded di-
epoxy derivative III (Scheme 1) [2]. It should be
noted that epoxidation of caryophyllene 4β,5α-epoxide
gave two epimeric diepoxy derivatives. The reaction of
II with peroxy acid was stereoselective.
Isomerization of compound III over solid catalysts
(
such as β-zeolite or askanite–bentonite clay) leads to
formation of dialdehyde IV and tricyclic hydroxy alde-
hyde Va; in addition, compounds VI and VII at a ratio
1
of 1:0.4 (according to the H NMR data) were isolated
from the reaction mixture. Compound IV and tricyclic
hydroxy aldehyde Vb (which is stereoisomeric to Va)
were obtained previously as a result of acid-catalyzed
The most stable conformations of diepoxide III are
almost equally strained αα and βα forms. The low
1
070-4280/05/4109-1280 © 2005 Pleiades Publishing, Inc.

TRANSFORMATIONS OF ISOCARYOPHYLLENE DIEPOXIDE
1281
Scheme 1.
Me
15
12Me
Me
Me
Me
Me
Me
14 Me
Me
3
7
1
1
2
O
4
O
[O]
[O]
1
9
5
1
0
6
8
1
3
H C
H C
2
2
O
I
II
III
Me
Me
OH
Me
Me
Me
Me
OH–
O
OH–
O
HO
HO
OH
O
2
.0
O
O
O
αα
βα
ΔE = 0.0 (E = –735.924867)
ΔH° = –45.9 (PM3)
0.1
f
–42.1 kcal/mol
transformations of caryophyllene diepoxides [1].
Scheme 2 illustrates a probable mechanism of trans-
formations of compound III in acid medium. In the
first stage, protonation of 8,13-epoxy ring gives cation
A which undergoes rearrangement to epoxy aldehyde
VI. Further transformations of compound VI follow
two pathways, a and b, which lead to dialdehyde IV
and hydroxy aldehyde Va, respectively. Pathway a in-
cludes protonation of the 4,5-epoxy ring with forma-
tion of ion B, and the subsequent C–C bond migration
is accompanied by contraction of the 9-membered ring
to produce compound IV (via elimination of proton).
Along pathway b, enolization of the aldehyde group,
followed by opening of the oxirane ring and cycliza-
tion, gives rise to tricyclic skeleton of V. The proposed
reaction scheme which begins with opening of the
compounds IX and X at a ratio of 1:1. Scheme 3
shows a probable mechanism of acid-catalyzed trans-
formations of diepoxy derivative III under homogene-
ous conditions. According to the results of quantum-
chemical and molecular-mechanics calculations, the
reactivity of the 8,13-epoxy ring is higher; therefore, it
is cleaved in the first stage. Further addition of water
molecule from the α-side is more favorable, and the
product is epoxy diol with a heat of formation of
–
130.9 kcal/mol. Opening of the 4,5-epoxy ring and
the subsequent transannular cyclization can occur
through both secondary and tertiary carbocation to
give more stable oxonium ion, ΔH° = 13.8 kcal/mol.
f
Carbocation with ΔH° = 2.3 kcal/mol is not formed,
f
presumably for kinetic reasons.
Thus we have shown that isomerization of iso-
caryophyllene diepoxide over solid catalysts either
yields bicyclic dialdehyde IV via contraction of the
8
,13-epoxy ring is supported by the facts that com-
pound VI in the presence of β-zeolite is converted into
IV and Va and that epoxy acid VII is formed from
aldehyde VI via oxidation with atmospheric oxygen.
9
-membered ring to 8-membered (compound IV is
also formed by isomerization of caryophyllene diepox-
ides) or involves rearrangement to hydroxy aldehyde
Va having a tricyclic skeleton. The isolation of epoxy
aldehyde VI from the reaction mixture supports our
assumptions concerning possible transformation path-
ways of diepoxy derivative III over acid β-zeolite.
Acid-catalyzed isomerization of compound III under
homogeneous conditions leads to formation of intra-
molecular heterocyclization products IX and X.
Next we examined transformations of diepoxy
derivative III in homogeneous acid media. Dissolution
of compound III in the system acetone–water–sulfuric
acid led to formation of tricyclic ether IX as a result of
intramolecular heterocyclization. The transformation
of isocaryophyllene diepoxide (III) in formic acid or in
the system formic acid–dioxane afforded a mixture of
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 41 No. 9 2005

1
282
SALOMATINA et al.
Scheme 2.
O
H+
O
O
O
~H
O
HO
HO
OCH
III
A
VI
O
O (atmospheric)
2
HOCO
VII
OH
Me
Me
H
CHO
Me
OH
a
~C–C
–
H+
O
O
OCH
B
IV
Me
Me
H
O
H+
b
OH
Me
OH
HO
HO
HO
1
5
Me
Me
H
Me
Me
H
Me
Me
H
1
4
2
2
1
1
1
3
12
Me
1
9
3
12
Me
9
4
Me
OH
4
–
H+
1
0
8
OH
OH
5
6
13
Me
5
O
O
7
1
3
Va
Vb
VIIIa–VIIId
1
2
13
12
13
12
13
12
13
VIII, α-C H
3
, β-OH, α-C H
3
(a); α-C H
3
, α-OH, α-C H
3
(b); β-C H
3
, α-OH, β-C H
3
(c); β-C H
3
, β-OH, β-C H
3
(d).
4
8
The structure of the newly synthesized compounds
bridge links C and C , the doublet at δ 86.64 ppm
C
1
13
13
was established on the basis of their H and C NMR
spectra. Comparison of the NMR spectra of compound
Va with the corresponding data for isomer Vb and four
isomeric alcohols VIIIa–VIIId [6] allowed us to as-
should be displaced upfield in the C NMR spectrum
recorded in the presence of D O. α-Orientation of the
methyl group on C and of the 5,8-oxygen bridge may
be assumed on the basis of the configuration of the
,5-epoxy group in the initial diepoxide, which is also
confirmed by the calculations. Identical stereochemical
structures of compounds IX and X follow from simi-
larity in their H and C NMR spectra.
2
4
4
8
sign α-orientation of the substituents on C and C and
4
5
β-orientation of the substituent on C .
4
The presence of a hydroxy group on C and of
1
13
5
,8-epoxy bridge in molecule IX is confirmed by the
C NMR spectrum of a solution of IX in a CCl4–
1
3
CDCl mixture containing D O. Isotope effect due to
EXPERIMENTAL
3
2
replacement of the OH group by OD induces upfield
shift of the singlet at δ 75.39 ppm (Δδ = 0.12 ppm)
The initial compounds and reaction products were
analyzed by GLC on a Biokhrom-1 chromatograph
equipped with a flame-ionization detector using SE-54
(13 000 × 0.22 mm) and VS-30 (an analog of SE-30;
C
C
4
belonging to C and of the triplet at δ 65.90 ppm
C
1
3
(
Δδ = 0.12 ppm) belonging to C . Otherwise, when
C
5
the hydroxy group is attached to C and the oxygen
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 41 No. 9 2005

TRANSFORMATIONS OF ISOCARYOPHYLLENE DIEPOXIDE
1283
Scheme 3.
O
H+
OH
O
O
OH
2.3
HO
OH
III
H+
123.3
15.0 ~H
O
O
H+
H O
2
OH
–
H+
OH
OH
HO
HO
HO
A, 114.3
H+ H O
–130.9
23.1
–
H+
~OH
5.5
2
O
OH
OH
OH
O
H
HO
HO
HO
HO
–
129.8
31.5
20.4
H+ 6.7
1
5
1
5
1
4
14
10
1
1
11
1
0
1
1
3
3
OH
2
4
OH
2
4
5
OH
9
O
9
7
6
HCOOH
7
6
8
8
HC 16
H+
5
12
12
–
HO
O
H
HO
O
O
O
1
3
13
1
3.8
IX, –151.5
X
1
13
2
0000×0.27 mm) quartz capillary columns; carrier gas
The H and C NMR spectra were recorded on
1
helium. The product mixtures were separated by
column chromatography on silica gel (100–160 μm;
Czechia). The specific optical rotations were measured
on a Polamat A polarimeter. The elemental composi-
tions were determined from the high-resolution mass
spectra which were recorded on a Finnigan MAT-8200
instrument.
a Bruker AM-400 spectrometer (400.13 MHz for H
and 100.61 MHz for C) from solutions in CCl4–
CDCl (1:1); the chemical shifts were measured rela-
tive to the chloroform signals (δ 7.24, δ 76.90 ppm).
The structure of the products was determined by anal-
ysis of the H NMR spectra (including H– H double
resonance technique), C NMR spectra with selective
and off-resonance decoupling from protons, two-
dimensional C– H correlation spectra (COSY, direct
1
3
3
C
1
1
1
1
3
The reactions were carried out over wide-pore
1
3
1
β-zeolite (SiO /Al O 22.4; pore size 0.75–0.80 nm;
oxide concentrations: Na O 0.01, Al O 4.50, SiO
5
2
2
3
1
coupling constants JCH = 135 Hz), and unidimensional
C– H correlation spectra (LRJMD, long-range coupl-
2
2
3
2
1
3
1
9.20, Fe O 0.08 wt %; manufactured by Tseosit,
2
3
Novosibirsk); the catalyst was calcined for 3 h at
00°C before use.
ing constants JCH = 10 Hz ). The atom numbering used
below corresponds to those given in Schemes 1–3.
5
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 41 No. 9 2005

1
284
SALOMATINA et al.
The barriers to conformational transitions were cal-
(2aR,4aR,5S,7aR,7bS)-5-Hydroxy-2,2,4a-tri-
methyldecahydrocyclobuta[e]indene-7a-carbalde-
culated by the PM3 method; the heats of formation of
carbocations and the barriers to rearrangements were
calculated by the AM1 method. The B3LYP/6-31G*
calculations were performed using GAMESS program
2
0
1
hyde (Va). [α] = –10.0° (c = 2.1, CHCl ). H NMR
5
80
3
1
5
spectrum, δ, ppm (J, Hz): 1.05 s (C H ), 1.10 s
(C H ), 1.14 s (C H ), 1.21 d.d (10-H, J = 11,
3
1
2
14
3
3
10,9
[
7] at the Information Technologies Department,
J10,10' = 10), 1.28–1.50 m (4H, 2-H, 3-H), 1.52 m
(1-H), 1.54 d.d (10'-H, J = 10, J10',9 = 7), 1.66 m (6-H),
Novosibirsk State University.
1
.72–1.87 m (7-H), 2.13 m (6'-H, J6',6 = 13, J6',5 = 8),
Caryophyllene isolated from clove oil was used,
α] = –13.8° (c = 4.3, CHCl3).
580
20
2.30 d.d.d (9-H, J9,1 = 12, J9,10 = 11, J = 7), 3.73 d.d
9,10'
[
1
3
(5-H, J5,6 = 9, J5,6' = 8), 9.51 s (13-H). C NMR spec-
Isomerization of caryophyllene into isocaryo-
phyllene [8]. A mixture of 20 g of caryophyllene and
.2 g of finely powdered selenium was heated for 5 h
1
2
3
trum, δ , ppm: 46.71 d (C ), 23.00 t (C ), 30.93 t (C ),
C
4
5
6
7
4
6
1
8.53 s (C ), 80.39 d (C ), 29.90 t (C ), 19.41 t (C ),
0.04 s (C ), 35.49 d (C ), 37.55 t (C ), 39.63 s (C ),
9.70 q (C ), 205.87 d (C ), 20.83 q (C ), 30.37 q
0
8
9
10
11
at 180–190°C under argon. The crude product, 19 g,
was subjected to column chromatography on silica gel
using hexane as eluent to isolate 16 g (80%) of iso-
12
13
14
15
+
(
C ). Found: m/z 236.11748 [M] . C H O . Calcu-
15 24 2
lated: M 236.11762.
2
5
0
caryophyllene (I), [α] = –15.0° (c = 5.4, CHCl3).
80
We failed to distinguish signals from some protons
Isocaryophyllene diepoxide (III) was synthesized
according to the procedure described in [2]. Treatment
of 6.70 g (0.032 mol) of isocaryophyllene (I) with
a solution of monoperoxyphthalic acid (0.0385 mol) in
diethyl ether (c = 0.0007 M), followed by recrys-
tallization from hexane, gave 2.50 g (35%) of 4β,5β-
monoepoxide II. Epoxidation of the latter afforded
1
for each compound in the H NMR spectrum of mix-
ture VI/VII due to their superposition.
{
(1R,4R,6S,9S,10R)-4,12,12-Trimethyl-5-oxa-
4
,6
tricyclo[8.2.0.0 ]dodec-9-yl}acetaldehyde (VI).
1
15
H NMR spectrum, δ, ppm (J, Hz): 0.94 s (C H ),
3
1
4
12
0
.97 s (C H ), 1.29 s (C H ), 1.22–1.35 m (2-H, 3-H),
3 3
2
0
1.34 d.d (10-H, J10,10' = 10, J10,9 = 10), 1.55 d.d (10'-H,
J = 10, J10',9 = 8), 2.48 m (9-H), 2.58 d.d.d (8-H, J8,9
11, J8,7 = 6, J8,7' = 3), 2.63 d.d (5-H, J5,6 = 12, J = 3),
2
1
(
1
1
.57 g (95.5%) of compound III, [α] = –21.1° (c =
580
1
=
.9, CHCl ). H NMR spectrum, δ, ppm (J, Hz): 0.88 s
3
14
15
12
5,6'
C H ), 0.91 s (C H ), 1.26 s (C H ), 1.78 m (1β-H),
3 3 3
13
9
.54 s (13-H), 1.48–2.15 m (other protons). C NMR
.28–1.38 m (3-H, 2-H), 1.42–1.62 m (7-H, 2'-H, 6-H),
.88–2.03 m (7'-H, 3'-H, 9-H, 6'-H), 1.32 d.d (10-H,
1
2
spectrum, δ , ppm: 49.67 d (C ), 25.97 t (C ), 34.53 t
C
3
4
5
6
(
(
(
C ), 61.17 s (C ), 63.79 d (C ), 23.53 t (C ), 18.81 t
C ), 49.25 d (C ), 37.44 d (C ), 34.91 t (C ), 36.13 s
C ), 22.09 q (C ), 202.30 d (C ), 21.01 q (C ),
J10,10' = 10, J10,9 = 10), 1.48 d.d (10'-H, J = 10, J10',9
=
7
8
9
10
8
), 2.41 d (13-H, J13,13' = 5), 2.54 d.d (13'-H, J = 5, 1),
.63 d.d.d (5-H, J5, 6 = 11, J5, 6' = 2.5, J = 1).
11
12
13
14
2
5, 3'
1
5
13
1
29.80 q (C ).
C NMR spectrum, δ , ppm: 48.10 d (C ), 25.73 t
C
2
3
4
5
(
(
(
(
C ), 33.45 t (C ), 60.89 s (C ), 64.10 d (C ), 23.55 t
C ), 30.94 t (C ), 58.33 s (C ), 40.78 d (C ), 34.71 t
C ), 33.82 s (C ), 22.30 q (C ), 55.58 t (C ), 22.41 q
C ), 29.58 q (C ). Found: m/z 236.11748 [M] .
{(1R,4R,6S,9S,10R)-4,12,12-Trimethyl-5-oxa-
6
7
8
9
4,6
tricyclo[8.2.0.0 ]dodec-9-yl}acetic acid (VII).
10
11
12
13
1
15
H NMR spectrum, δ, ppm (J, Hz): 0.92 s (C H ),
3
1
4
15
+
14
12
0.93 s (C H ), 1.31 s (C H ), 2.42 m (9-H), 2.67 d.d
3 3
C H O . Calculated: M 236.11762.
(5-H, J5,6 = 12, J5,6' = 3), 3.73 d.d.d (8-H, J8,9 = 11,
15
24
2
J
= 6, J8,7' = 4), 1.22–2.08 m (other protons).
8
,7
Isomerization of isocaryophyllene diepoxide (III)
over β-zeolite. A solution of 0.40 g of compound III in
0 ml of methylene chloride was added to 0.70 g of
freshly calcined β-zeolite. The mixture was stirred for
0 min and filtered. According to the GLC data, the
mixture contained compounds IV, Va, and VI at a ratio
of 3:2:1. The product mixture, 0.39 g, was subjected
to column chromatography on silica gel (gradient
elution with hexane–diethyl ether, 0 to 80% of the
latter) to isolate 0.07 g (18%) of compound IV, 0.12 g
1
3
1
C NMR spectrum, δ , ppm: 48.75 d (C ), 25.90 t
C
2
3
4
5
(
C ), 34.60 t (C ), 61.26 s (C ), 63.67 d (C ), 23.64 t
1
6
7
8
9
(
C ), 20.88 t (C ), 41.64 d (C ), 39.27 d (C ), 34.87 t
1
0
11
12
13
(
C ), 36.13 s (C ), 22.09 q (C ), 179.55 s (C ),
5
1
4
15
2
0.98 q (C ), 29.80 q (C ).
Transformations of isocaryophyllene diepoxide
(III) under homogeneous conditions. a. In the system
acetone–water–sulfuric acid. Compound III, 0.20 g,
was dissolved in 3 ml of a mixture of acetone, water,
and sulfuric acid at a ratio of 50:6:1 (by volume).
After 2 h, the mixture was treated with a saturated
aqueous solution of Na CO and extracted with diethyl
(
31%) of Va, and 0.04 g of mixture VI/VII (1:0.4).
The spectral parameters of compound IV were re-
ported in [1].
2
3
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 41 No. 9 2005

TRANSFORMATIONS OF ISOCARYOPHYLLENE DIEPOXIDE
1285
ether (3×30 ml), and the extract was dried over
3-H), 3.99 t (5-H, J5,6 = 7.5), 2.08–2.20 m (2H, 6-H),
1.76 d.d.d (7-H, J7,7' = 12, J7,6 = 12, J7,6' = 10), 1.96–
2.03 m (7'-H), 2.04 d.d.d (9α-H, J9,1 = 10, J9,10 = 10,
J9,10' = 8), 1.12 d.d (10-H, J10,10' = 10, J10,9 = 10),
1.47 d.d (10'-H, J = 10, 8), 3.89 d.d (13-H, J13,13' = 12,
MgSO . According to the GLC data, the extract con-
4
tained compound IX. The solvent was distilled off, and
the residue, 0.16 g, was subjected to column chroma-
tography on silica gel (gradient elution with hexane–
diethyl ether, 0 to 100% of the latter) to isolate 0.08 g
J13,16 = 1), 3.99 d.d (13'-H, J = 12, J
= 1), 8.06 t
13',16
1
3
(
37%) of compound IX.
(16-H, J16,13 = 1). C NMR spectrum, δ , ppm:
C
1
2
3
4
4
7.81 d (C ), 25.64 t (C ), 39.07 t (C ), 75.30 s (C ),
(
1S,2S,5R,8R,9S)-1-Hydroxymethyl-4,4,8-tri-
5
6
7
8
2
,5
85.63 d (C ), 26.03 t (C ), 27.33 t (C ), 85.08 s (C ),
methyl-12-oxatricyclo[7.2.1.0 ]dodecan-8-ol (IX).
9
10
11
12
2
0
1
44.63 d (C ), 35.78 t (C ), 35.36 s (C ), 27.33 q (C ),
[
α] = –10.0° (c = 1.0, CHCl ). H NMR spectrum, δ,
580 3
13
14
15
1
4
15
67.26 t (C ), 20.82 q (C ), 29.76 q (C ), 160.79 d
ppm (J, Hz): 0.95 s (C H ), 0.96 s (C H ), 1.27 s
3
3
16
+
12
(C ). Found, m/z: [M – CHO] 237.16868. C15
H
25
O
3
.
(
C H ), 1.42 br.d.d (1β-H, J = 10, J1,9 = 10), 1.14–
3 1,2
+
Calculated: [M – CHO] 237.16979.
1
.25 m and 1.47–1.56 m (1H each, 2-H), 1.56–1.70 m
The authors are grateful to the Russian Foundation
for Basic Research for providing access to the STN
database (project no. 00-03-32721) through the STN
Center at the Novosibirsk Institute of Organic Chem-
istry; they also thank post-graduate student A.A. Ro-
manenko (Parallel Calculation Department) and
student V.P. Vysotskii (Novosibirsk State University)
for their help in performing the calculations.
(
6
1
2H, 3-H), 3.95 t (5-H, J5,6 = 7.5), 2.08–2.16 m (2H,
-H), 1.82–1.93 m (2H, 7-H), 1.92 d.d.d (9α-H, J9,1
=
0, J9,10 = 10, J9,10' = 8), 1.07 d.d (10-H, J10,10' = 10,
J10,9 = 10), 1.46 d.d (10'-H, J = 10, 8), 2.27 br.s (2H,
OH), 3.18 d and 3.33 d (1H each, 13-H, AB system,
J = 11.5). C NMR spectrum, δ , ppm: 47.83 d (C ),
2
2
3
(
[
1
3
1
C
2
3
4
5
5.78 t (C ), 39.14 t (C ), 75.39 s (C ), 86.64 d (C ),
6
7
8
9
6.44 t (C ), 26.01 t (C ), 87.62 s (C ), 44.78 d (C ),
1
0
11
12
5.51 t (C ), 35.58 s (C ), 27.38 q (C ), 65.90 t
1
3
14
15
REFERENCES
C ), 20.92 q (C ), 29.87 q (C ). Found, m/z:
M] 254.13174. C H O . Calculated: M 254.13067.
+
1
5
26
3
1
. Salomatina, O.V., Korchagina, D.V., Gatilov, Yu.V.,
Polovinka, M.P., and Barkhash, V.A., Russ. J. Org.
Chem., 2004, vol. 40, p. 1441.
b. In the system HCOOH–dioxane. Compound III,
.50 g, was dissolved in a mixture of 0.5 ml of formic
0
acid and 0.5 ml of dioxane. After 30 min, the mixture
was treated with a saturated aqueous solution of
Na CO and extracted with diethyl ether (3×30 ml).
2. Collado, I.G., Hanson, J.R., and Macias-Sanchez, A.J.,
Nat. Prod. Rep., 1998, p. 187.
3. Khomenko, T.M., Bagryanskaya, I.Yu., Gatilov, Yu.V.,
Korchagina, D.V., Gatilova, V.P., Dubovenko, Zh.V., and
Barkhash, V.A., Zh. Org. Khim., 1985, vol. 21, p. 677.
2
3
The extract was dried over MgSO . According to the
4
GLC data, it contained compounds IX and X at a ratio
of 1:1. The solvent was distilled off from the extract,
and the residue, 0.40 g, was subjected to column
chromatography on silica gel (gradient elution with
hexane–diethyl ether, 0 to 100% of the latter) to isolate
4
. Warnhoff, E.W. and Srinivasan, V., Can. J. Chem., 1973,
vol. 51, p. 3955.
5
. Srinivasan, V. and Warnhoff, E.W., Can. J. Chem., 1976,
vol. 54, p. 1372.
6
7
. Tkachev, A.V., Zh. Org. Khim., 1989, vol. 25, p. 122.
0
.05 g (9%) of compound IX and 0.03 g (6%) of X.
. Schmidt, M.W., Baldridge, K.K., Boatz, J.A., Elbert, S.T.,
Gordon, M.S., Jensen, J.H., Koseki, S., Matsunaga, N.,
Nguyen, K.A., Su, S.J., Windus, T.L., Dupuis, M., and
Montgomery, J.A., J. Comput. Chem., 1993, vol. 14,
p. 1347.
(
1S,2S,5R,8R,9S)-8-Hydroxy-4,4,8-trimethyl-12-
2
,5
oxatricyclo[7.2.1.0 ]dodec-1-ylmethyl formate (X).
2
0
1
[
α] = –5.2° (c = 1.9, CHCl ). H NMR spectrum, δ,
580 3
1
4
15
ppm (J, Hz): 0.96 s (C H ), 0.97 s (C H ), 1.30 s
3
3
12
(
C H ), 1.42 br.d.d (1β-H, J = 10, J1,9 = 10), 1.17–
8. Rachlin, S., US Patent no. 3621070, 1971; Ref. Zh.,
Khim., 1972, no. 14R448.
3
1,2
1.27 m and 1.49–1.54 m (2H, 2-H), 1.54–1.71 m (2H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 41 No. 9 2005