Preparation of 3-bromomethyl-3-butenal diethylacetal and its conversion into isoprenoid aldehydes derivatives

Article abstract of DOI:10.1134/S1070428009110086

The cyclopropanation of ethyl 3,3-diethoxypropionate with alkoxytitanacyclopropane reagents followed by the cleavage of the three-membered carbocycle in the formed cyclopropyl mesylate provided in a good yield 3-bromomethyl-3-butenal diethylacetal. The la

Full text of DOI:10.1134/S1070428009110086

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 11, pp. 1623−1632. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © I.V. Mineeva, O.G. Kulinkovich, 2009, published in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 11, pp. 1634−1643.
Preparation of 3-Bromomethyl-3-butenal Diethylacetal
and Its Conversion into Isoprenoid Aldehydes Derivatives
I. V. Mineeva and O. G. Kulinkovich
Belarus State University, Minsk, 220030 Belarus
e-mail: kulinkovich@bsu.by
Received October 28, 2008
Abstract—The cyclopropanation of ethyl 3,3-diethoxypropionate with alkoxytitanacyclopropane reagents
followed by the cleavage of the three-membered carbocycle in the formed cyclopropyl mesylate provided in
a good yield 3-bromomethyl-3-butenal diethylacetal. The latter was brought into reactions of aldehyde allylation
and cross-coupling with allyl halides in the intermediate stages at the generation of carbanionic intermediates.
The conversion of compounds obtained into the corresponding β, γ- or α,β-unsaturated aldehydes demonstrated
the opportunity of applying 3-bromomethyl-3-butenal diethylacetal as a C5-isoprenoid building block.
DOI: 10.1134/S1070428009110086
hydrolysis of the latter with the hydrobromic acid in
acetone [7] or in a two-phase system hydrochloric acid–
dichloroethane [8] is accompanied by the dehydration
leading to the formation of mixtures similar in the
stereoisomers composition containing cis- and trans-
dehydrocitrals VIa and retinals VIb with the content of
the trans-isomers not exceeding 75%. The hydrolysis
with the hydrochloric acid of cyclic acetal VIIa which
cleanly formed by keeping hydroxyacetal Va in the
presence of p-toluenesulfonic acid resulted in trans-
dehydrocitral VIa [9–16] with 90% diastereoselectivity.
Under the same conditions the relative content of trans-
retinal VIb in the hydrolysis products of precursor Vb
did not essentially increase. Inasmuch as an efficient
procedure for the conversion of a mixture of cis- and
trans-retinals VIb into a pure trans-isomer was published
[7], we did not attempt to improve the stereoselectivity
of its formation from compound Vb. The hydrolysis of
cyclic acetals VIIa, VIIc–VIIe without dehydration and
the shift of the multiple bond cleanly occurred in aqueous
We recently developed a convenient method of the
preparation of methyl 3-bromomethyl-3-butenoate and
the procedure for its application to the allylation of
electrophiles in the presence of zinc in a water-organic
medium [1]. The use of this compound as a nucleophilic
C5-isoprenoid building block made it possible to obtain
the corresponding esters both with the methylene- and
the methyl-substituted carbon skeleton [1–3]. In this study
an analogous approach was extended to the preparation
of 3-bromomethyl-3-butenal diethylacetal (I) by the
cyclopropanation of an available ethyl 3,3-diethoxy-
propionate (II) with ethylmagnesium bromide in the
presence of titanium(IV) isopropoxide [4, 5] followed by
subsequent mesylation and by the treatment of obtained
mesylate III with magnesium bromide in anhydrous ethyl
ether [1, 6] (Scheme 1).
Allyl bromide I readily condensed with aldehydes IVa–
IVe under the treatment with zinc activated with
dibromoethane in tetrahydrofuran forming the
corresponding aldol acetals Va–Ve (Scheme 2). The
Scheme 1.
(1) EtMgBr_Ti(OPr-i)4
OEt OMs
OEt
O
OEt
(2) MsCl_Et3N
Mg + BrCH2BrCH2 +Et2O
88%
Br
EtO
EtO
OEt
EtO
85%
III
1623
II
I

MINEEVA, KULINKOVICH
1624
Scheme 2.
HBr_H2O_Me2CO
or
O
OH
HCl_H2O_C2H4Cl2
O
EtO
EtO
Zn_THF
71_89%
I
+
65_88%
H
R
R
R
H
IVa_IVe
VIa_VIe
Va_Ve
EtOH
n-TsOH
(CH2Cl2)
91_96%
HBr_H2O_Me2CO
or
HCl_H2O_C2H4Cl2
AcOH_H2O
71_79%
68_81%
HO
O
R
EtO
O
R
VIIa, VIIc_VIIe
VIIIa, VIIId, VIIIe
R = CH=C(CH3)2 (a),
(b), CH2CH(CH3)2 (c), Ph (d), CH2OBn (d).
[21] gave quantitatively the corresponding acetals of
β-methylene-substituted aldehydes XI and XIV
(Scheme 4). The condensation of compound I with allyl
sulfone XV in the presence of lithium diisopropylamide
at low temperature resulted in a moderate yield of acetal
XVI, whereas at the use as a base of potassium tert-butyl-
ate and the reaction performance in the boiling benzene
the elimination of tolyl sulfinate occurred with the forma-
tion of compound XVII whose hydrolysis gave rise to a mix-
ture of cis- and trans-dehydrocitrals VIa in a ratio 1:5.
acetic acid [17], whereas acyclic hydroxyacetals Va–
Ve under these conditions were converted into complex
mixtures of compounds.
The reductive elimination by treating with sodium in
ethanol [18] of the arenesulfonyl group of compound IX
obtained by the alkylation of sulfone X with prenyl
bromide afforded an acetals mixture of β,γ-unsaturated
aldehydes XI and XII in a ratio 1:4 (Scheme 3). In the
hydrolysis of the mixture in the presence of pyridinium
p-tolyenesulfonate [19] the corresponding trienals formed
in approximately the same stereoisomers ratio, whereas
the treatment of the acetals mixture XI and XII with the
aqueous formic acid in petroleum ether [20] provided an
aldehyde with nonconjugated trans-trisubstituted double
bond XIII that was isolated in an individual state by
column chromatography.
The studied reactions of 3-bromomethyl-3-butenal
diethylacetal (I) leading to the formation of carbon-carbon
bonds and the stereoselective conversions of the formed
compounds demonstrate the versatile opportunities of its
application as a C5-isoprenoid building block that we plan
to use in the preparation of naturally occurring compounds
of more complex structures.
In addition to the above described conversions func-
tionally substituted allyl bromide I was brought into reac-
tions of carbon-carbon bonds formation as an electrophilic
substrate. Its reaction with allylmagnesium chloride or
prenylmagnesium chloride in the presnce of copper iodide
EXPERIMENTAL
1H and 13C NMR spectra were registered on a spec-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

PREPARATION OF 3-BROMOMETHYL-3-BUTENALDIETHYLACETAL
1625
Scheme 3.
(1) BuLi_THF, _78oC
(2)
EtO
EtO
EtO
EtO
TolSO2Na
75%
SO2Tol
I
X
SO2Tol
BrH
Br
84%
Na_EtOH , _78oC
90%
EtO
EtO
EtO
+
EtO
XI
XII
O
HCO2H_H2O
65%
H
XIII
Scheme 4.
R
R
MgCl,
CuI
or
Li2CuCl4
95_98%
R
OEt
R
EtO
OEt
XI, XIV
I
_
_
(1) Me2CO n-TsO Py+
(2) Et3N_Et2O
TolSO2
OEt
SO2Tol
LDA, _78oC
50%
XV
VIa
PhH_t-BuOK, 80oC
70%
EtO
EtO
78%
XVII
XVI
trometer Bruker AC 400 at operating frequencies 400
and 100 MHz respectively from solutions in
deuterochloro-form. IR spectra were recorded on
spectrophotometers Specord 75IR and Vertex 70 from
solutions of compounds in CCl4. The isolation of individual
substances was carried out by column chromatography
on silica gel (70–230 mesh). All solvents before use
were purified and distilled by standard procedures. The
elemental analysis was performed by semimicro method.
3-Bromomethyl-3-butenal diethylacetal (I). To a
solution of MgBr2 obtained from 2.90 g (120 mmol) of
magnesium turnings and 10.4 ml of 1,2-dibromoethane in
60 ml of anhydrous ethyl ether was added dropwise at
stirring a solution of 16.92 g (60 mmol) of cyclopropyl
mesylate III [1] in 100 ml of the same solvent. On
completion of the reaction (TLC monitoring) was added
at cooling 100 ml of water, the organic layer was
separated, the water layer was extracted with ethyl ether
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

MINEEVA, KULINKOVICH
1626
dien-5-ol (Vb). Yield 2.06 g (71%). IR spectrum, ν, cm–1:
3617 (OH), 3466 (OH), 1127 (C–O), 1058 (C–O).
1H NMR spectrum, δ, ppm: 0.98 br.s (3H, CH3),
0.99 br.s (3H, CH3), 1.20 t (6H, 2 CH3CH2O, J 6.9 Hz),
1.42–1.47 m [2H, CH2C(CH3)2], 1.56–1.62 m (2H,
CH2CH2CH2), 1.67 br.s (3H, CH3), 1.85 br.s (3H, CH3),
1.97–2.00 m (2H, CH2CCH3), 2.25–2.37 m (3H,
CH2CHOH, OH), 2.39–2.43 m (2H, CCH2CH), 3.48–
3.56 m (2H, CH3CH2O), 3.63–3.71 m (2H, CH3CH2O),
4.60–4.68 m (1H, CHCHOH), 4.64 t (1H, OCHO,
J 5.9 Hz), 4.99 br.s (1H, CH2=), 5.00 br.s (1H, CH2=),
5.40 d (1H, CHCHOH, J 8.5 Hz), 5.99 d (1H, CCHCH,
J 16.1 Hz), 6.09 d (1H, CCHCH, J 16.1 Hz). 13C NMR
spectrum, δ, ppm: 12.81 (CH3), 15.16 (CH3), 15.21
(CH3), 19.24 (CH2), 21.56 (CH3), 28.84 (CH3), 32.86
(CH2), 34.16 (C), 39.50 (CH2), 39.95 (CH2), 45.38 (CH2),
61.34 (CH2), 61.53 (CH2), 66.45 (CH), 102.51 (CH),
115.81 (CH2=), 126.66 (CH=), 128.84 (C), 132.16 (CH=),
135.68 (C), 137.15 (CH=), 137.57 (C), 141.81 (C). Found,
%: C 83.76; H 6.97. C24H40O3. Calculated, %: C 83.69;
H 7.02.
(3×50 ml). The combined organic solutions were washed
with a saturated water solution of NaHCO3 (3 × 25 ml),
NaCl (25 ml), and it was dried with MgSO4. On removing
the solvent at a reduced pressure and on the separation
of the reaction product by column chromatography (eluent
benzene) we obtained 12.48 g (88%) of substituted acetal
I as an oily fluid quickly yellowing on storage. IR spec-
trum, ν, cm–1: 1208 (C–O), 1124 (C–O), 1064 (C–O).
1H NMR spectrum, δ, ppm: 1.19 t (6H, 2 CH3CH2O,
J 7.0 Hz), 2.52 d (2H, CH2CH, J 5.6 Hz), 3.46–3.54 m
(2H, CH3CH2O), 3.62–3.70 m (2H, CH3CH2O), 4.04 br.s
(2H, CH2Br), 4.62 t (1H, OCHO, J 5.6 Hz), 5.06 br.s
(1H, CH2=), 5.25 br.s (1H, CH2=). 13C NMR spectrum,
δ, ppm: 15.20 (2 CH3), 37.36 (CH2Br), 37.49 (CH2),
61.31 (2 CH2), 101.83 (CH), 117.81 (CH2=), 141.38 (C).
Found, %: C 43.35; H 6.27. C9H17BrO2. Calculated, %:
C 43.26; H 6.35.
Condensation of 3-bromomethyl-3-butenal
diethylacetal (I) with aldehydes IVa–IVe. To a mix-
ture of 1.82 g (7.7 mmol) of compound I in 5 ml of THF
and 7.7 mmol of aldehyde IVa–IVe was added 0.55 g
(8.46 mmol) of zinc, several drops of dibromoethane, and
the reaction mixture was heated at stirring for 30 min.
After treating with water (20 ml) the organic layer was
separated, the water layer was extracted with ethyl ether
(3×15 ml), the combined organic solutions were dried with
Na2SO4. On removing the solvent at a reduced pressure
and on the separation of the reaction product by column
chromatography (eluent petroleum ether–ethyl acetate,
10:1) we obtained aldol acetates Va–Ve as colorless oily
fluids.
2-Methyl-6-methylene-8,8-diethoxyoctan-4-ol
(Vc). Yield 1.41 g (75%). IR spectrum, ν, cm–1: 3485
1
(OH), 1127 (C–O), 1062 (C–O). H NMR spectrum, δ,
ppm: 0.86–0.88 m [6H, 2 CH(CH3)2], 1.13–1.17 m [7H,
2 CH3CH2O, CH2CH(CH3)2], 1.34–1.42 m [1H,
CH2CH(CH3)2], 1.71–1.79 m [1H, CH(CH3)2], 2.03 d.d
(1H, CH2CHOH, J1 13.5, J2 9.5 Hz), 2.22–2.29 m (1H,
CH2CHOH), 2.30 br.s (1H, OH), 2.33–2.35 m (2H,
CH2C), 3.42–3.49 m (2H, CH3CH2O), 3.58–3.65 m (2H,
CH3CH2O), 3.73–3.79 m (1H, CHOH), 4.60 t (1H,
OCHO, J 5.8 Hz), 4.90 br.s (1H, CH2=), 4.93 br.s (1H,
CH2=). 13C NMR spectrum, δ, ppm: 15.07 (CH3), 15.09
(CH3), 22.06 (CH3), 23.27 (CH3), 24.55 (CH), 39.77
(CH2), 45.82 (CH2), 46.25 (CH2), 61.10 (CH2), 61.37
(CH2), 67.02 (CH), 102.38 (CH), 115.27 (CH2=), 142.41
(C). Found, %: C 68.90; H 11.43. C14H28O3. Calculated,
%: C 68.81; H 11.55.
2-Methyl-6-methylene-8,8-diethoxyoct-2-en-4-
ol (Va). Yield 1.49 g (80%). IR spectrum, ν, cm–1: 3617
1
(OH), 3473 (OH), 1127 (C–O), 1058 (C–O). H NMR
spectrum, δ, ppm: 1.19 t (6H, 2 CH3CH2O, J 6.9 Hz),
1.68 br.s (3H, CH3), 1.71 br.s (3H, CH3), 2.15–2.29 m
(3H, CH2CHOH, OH), 2.37 d.d (1H, CH2C, J1 15.6,
J2 5.6 Hz), 2.41 d.d (1H, CH2C, J1 15.6, J2 5.9 Hz), 3.45–
3.53 m (2H, CH3CH2O), 3.61–3.69 m (2H, CH3CH2O),
4.49 d.t (1H, CHOH, J1 8.2, J2 4.9 Hz), 4.62 t (1H, OCHO,
J 5.9 Hz), 4.56 br.s (1H, CH2=), 4.97 br.s (1H, CH2=),
5.17 d (1H, CH=, J 8.2 Hz). 13C NMR spectrum, δ, ppm:
15.14 (CH3), 15.17 (CH3), 18.19 (CH3), 25.68 (CH3),
39.85 (CH2), 45.37 (CH2), 61.25 (CH2), 61.46 (CH2),
66.34 (CH), 102.39 (CH), 115.53 (CH2=), 127.37 (CH=),
134.75 (C), 141.93 (C). Found, %: C 69.92; H 10.72.
C14H26O3. Calculated, %: C 69.83; H 10.81.
3-Methylene-5,5-diethoxy-1-phenylpentan-1-ol
(Vd). Yield 1.81 g (89%). IR spectrum, ν, cm–1: 3540
1
(OH), 3492 (OH), 1127 (C–O), 1059 (C–O). H NMR
spectrum, δ, ppm: 1.22 t (6H, 2 CH3CH2O, J 7.0 Hz),
2.42 d.d (1H, CH2CHOH, J1 14.1, J2 9.7 Hz), 2.46 d
(2H, CH2C, J 5.9 Hz), 2.55 d.d (1H, CH2CHOH, J1 14.1,
J2 3.1 Hz), 2.80 br.s (1H, OH), 3.48–3.56 m (2H,
CH3CH2O), 3.65–3.73 m (2H, CH3CH2O), 4.66 t (1H,
OCHO, J 5.9 Hz), 4.85 d.d (1H, CHOH, J1 9.7, J2 3.3 Hz),
5.04 br.s (2H, CH2=), 7.24–7.39 m (5H, Ph). 13C NMR
spectrum, δ, ppm: 15.16 (2 CH3), 39.70 (CH2), 47.63
(1Ε,3E)-3-Methyl-7-methylene-1-(2,6,6-
trimethyl-cyclohex-1-enyl)-9,9-diethoxynona-1,3-
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

PREPARATION OF 3-BROMOMETHYL-3-BUTENALDIETHYLACETAL
1627
(CH2), 61.30 (CH2), 61.60 (CH2), 71.78 (CH), 102.46
(CH), 116.12 (CH2=), 125.70 (C2,6arom), 127.28 (C3,5
arom), 128.31 (C4 arom), 142.01 (C1 arom), 144.14 (C).
Found, %: C 72.78; H 9.07. C16H24O3. Calculated, %:
C 72.69; H 9.15.
(2ΕZ,4E,6Ε,8E)-3,7-Dimethyl-9-(2,6,6-tri-
methyl-1-cyclohexenyl)-2,4,6,8-nonatetraenal
(retinal) (VIb). Yield 0.34 g (60%). The spectral
characteristics of the obtained isomers mixture are
consistent with those described in [22].
1-(Benzyloxy)-4-methylene-6,6-diethoxyhexan-
2-ol (Ve). Yield 1.80 g (76%). IR spectrum, ν, cm–1:
3591 (OH), 3510 (OH), 1160 (C–O), 1116 (C–O). 1H NMR
spectrum, δ, ppm: 1.18 t (3H, CH3CH2O, J 6.9 Hz),
1.19 t (3H, CH3CH2O, J 6.9 Hz), 1.83 br.s (0.3H, OH),
2.23 d.d (1H, CCH2CH, J1 14.1, J2 8.5 Hz), 2.30 d.d
(1H, CCH2CH, J1 14.1, J2 4.6 Hz), 2.40 d (2H, CH2C,
J 5.9 Hz), 2.69 br.s (0.7H, OH), 3.40 d.d (1H, CH2OBn,
J1 9.5, J2 6.9 Hz), 3.46–3.53 m (3H, CH2OBn,
CH3CH2O), 3.61–3.69 m (2H, CH3CH2O), 3.97–4.03 m
(1H, CHOH), 4.56 br.s (2H, CH2Ph), 4.63 t (1H, OCHO,
J 5.9 Hz), 4.96 br.s (1H, CH2=), 4.97 br.s (1H, CH2=),
7.27–7.36 m (5H, CH2Ph). 13C NMR spectrum, δ, ppm:
15.16 (2 CH3), 39.89 (CH2), 40.94 (CH2), 61.13 (CH2),
61.26 (CH2), 68.48 (CH), 73.30 (CH2), 74.08 (CH2),
102.19 (CH), 115.29 (CH2=), 127.66 (C2,4,6 arom), 128.35
(C3,5 arom), 137.99 (C1 arom), 141.63 (C). Found, %:
C 70.14; H 9.06. C18H28O4. Calculated, %: C 70.10;
H 9.15.
(2Ε,4E)-3,7-Dimethylocta-2,4-dienal (VIc). Light-
yellow oily fluid with a pleasant grass odor. Yield 0.25 g
(88%). IR spectrum, ν, cm–1: 1672 (C=O), 1633 (C=C),
1
1206 (C–O), 1116 (C–O). H NMR spectrum, δ, ppm:
0.89 br.s [3H, CH(CH3)2], 0.90 br.s [3H, CH(CH3)2],
1.67–1.76 m [1H, CH(CH3)2], 2.04–2.12 m [2H,
CH2CH(CH3)2], 2.23 s (3H, CH3C), 5.86 d (1H, CHCO,
J 8.2 Hz), 6.16 d (1H, CCHCH, J 16.1 Hz), 6.24 t (1H,
CH2CHCH, J 7.2 Hz), 10.08 d (1H, CHO, J 8.2 Hz).
13C NMR spectrum, δ, ppm: 13.04 (CH3), 22.29 (2 CH3),
28.32 (CH), 42.43 (CH2), 128.36 (CH=), 134.40 (CH=),
138.46 (CH=), 154.74 (C), 191.41 (C). Found, %: C 78.96;
H 10.43. C10H16O. Calculated, %: C 78.90; H 10.59.
(2ΕZ,4E)-6-(Benzyloxy)-3-methylhexa-2,4-
dienal (VIe). Light-yellow oily fluid. Yield 0.28 g (80%).
IR spectrum, ν, cm–1: 1673 (C=O), 1640 (C=C), 1240
(C–O), 1206 (C–O), 1106 (C–O). 1H NMR spectrum, δ,
ppm: 2.17 br.s (3H, CH3), 4.08 d (2H, CH2OBn, J 5.1 Hz),
4.49 br.s (2H, CH2Ph), 5.86 d (1H, CHCO, J 7.9 Hz),
6.24 d.t (1H, CHCH2OBn, J1 15.9, J2 5.1 Hz), 6.35 d
(1H, CHCHCH2, J 15.9 Hz), 7.21–7.27 m (5H, Ph),
10.02 d (1H, CHO, J 7.9 Hz). 13C NMR spectrum, δ,
ppm: 12.99 (CH3), 69.94 (CH2), 72.73 (CH2), 126.04 (C2
arom), 127.73 (C4,6 arom), 127.80 (C3 arom), 128.45 (C5
arom), 129.76 (CH2=), 134.08 (CH=), 134.16 (CH=),
137.73 (C1 arom), 153.55 (C), 191.40 (CO). Found, %:
C 77.83; H 7.37. C14H16O2. Calculated, %: C 77.75; H 7.46.
Unsaturated aldehydes VIa–VIc, VIe. a. To a solu-
tion of 2 mmol of aldol acetal Va–Ve in 20 ml of boiling
acetone was added 1 ml of water and 0.5 ml of 48%
hydrobromic acid. After 1 h the reaction mixture was
treated with a saturated solution of NaHCO3 (10 ml),
the reaction product was extracted into dichloromethane
(3×15 ml), the combined extracts were dried with
MgSO4. On removing the solvent at a reduced pressure
and on the separation of the reaction product by column
chromatography (eluent petroleum ether–ethyl acetate,
40:1) we obtained the corresponding unsaturated
aldehydes VIa–VIc, VIe as a mixture of cis- and trans-
isomers, 1:3.
Preparation of unsaturated aldehydes VIa and
VId at treatment with hydrochloric acid. b. To a solu-
tion of 1 mmol of aldol acetal Va or Vd in 4 ml of
dichloroethane was added 4 ml of 10% HCl, and the
mixture was vigorously stirred for 12 h. The reaction
mixture was diluted with 30 ml of dichloromethane,
washed with the saturated water solution of NaHCO3
(15 ml), and dried with MgSO4. On removing the solvent
at a reduced pressure and on the separation of the
reaction product by column chromatography (eluent
petroleum ether–ethyl acetate, 30:1) we obtained the
target aldehydes VIa and VId as a mixture of cis- and
trans-isomers, 1:3. Compound VIa. Yield 0.11 g (73%).
(2ΕZ,4E)-3,7-Dimethylocta-2,4,6-trienal (VIa).
Light-yellow oily fluid with a pleasant grass odor. Yield
0.24 g (80%). IR spectrum, ν, cm–1: 1640 (C=O). 1H NMR
spectrum, δ, ppm: 1.87 br.s [6H, CH=C(CH3)2], 2.29 br.s
[3H, CHC(CH3)], 5.94 d (1H, CCHCO, J 8.5 Hz), 5.99 d
[1H, CH=C(CH3)2, J 11.3 Hz], 6.23 d (1H, CCHCH,
J 15.1 Hz), 6.96 d.d (1H, CHCHCH, J1 15.1, J2 11.3 Hz),
10.09 d (1H, CHO, J 8.5 Hz). 13C NMR spectrum, δ,
ppm: 13.06 (CH3), 18.87 (CH3), 26.51 (CH3), 125.39
(CH=), 128.67 (CH=), 132.52 (CH=), 132.62 (CH=),
142.46 (C), 155.17 (C), 191.11 (C). Found, %: C 79.99;
H 9.24. C10H14O. Calculated, %: C 79.96; H 9.39.
(2ΕZ,4E)-3-Methyl-5-phenylpenta-2,4-dienal
(VId). Bright yellow oily fluid. Yield 0.11 g (65%). IR
spectrum, ν, cm–1: 1671 (C=O), 1616 (C=C), 1250 (C–
1
O). H NMR spectrum, δ, ppm: 2.40 br.s (3H, CH3),
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

MINEEVA, KULINKOVICH
1628
6.09 d (1H, CHCHO, J 7.9 Hz), 6.91 d (1H, CHPh,
J 16.1 Hz), 7.08 d [1H, CHC(CH3), J 16.1 Hz], 7.33–
7.40 m (3H, H3,4,5 arom), 7.51 d (2H, H2,6 arom,
J 7.2 Hz), 10.17 d (1H, CHO, J 7.9 Hz). 13C NMR
spectrum, δ, ppm: 13.07 (CH3), 127.34 (C2,6 arom),
128.88 (C3,5 arom), 129.21 (C4 arom), 130.07 (CH),
131.31 (CH), 135.68 (CH), 135.85 (C1 arom), 154.19
(C), 191.22 (C). Found, %: C 83.76; H 6.97. C12H12O.
Calculated, %: C 83.69; H 7.02.
CH3CH2O, J 7.2 Hz), 1.24 t (3H, CH3CH2O, J 6.9 Hz),
1.45–1.52 m [1H, CH2CH(CH3)2], 1.57–1.64 m [1.2H,
CH2CH(CH3)2], 1.77–1.89 m [2H, CH(CH3)2,
CH2CH(CH3)2], 1.92–2.00 m [2.4H, CH(CH3)2,
CH2CH(CH3)2], 2.10–2.14 m (2H, CH2CHCH2), 2.19–
2.23 m (2H, CHCH2C), 2.28–2.35 m (2.4H,
CH2CHCH2), 2.38–2.43 m (2.4H, CHCH2C), 3.30–
3.37 m (1H, CH2CHCH2), 3.44–3.57 m (2.2H,
CH3CH2O), 3.66–3.74 m (1.2H, CH3CH2O), 3.79–
3.85 m (1.2H, CH2CHCH2), 3.91–3.99 m (1H,
CH3CH2O), 4.31 d.d (1H, CHOCH2, J1 9.5, J2 2.3 Hz),
4.75–4.78 m (3.6H, CHOCH2, CH2=), 4.92 br.s (1H,
CH2=), 4.93 br.s (1H, CH2=). 13C NMR spectrum, δ,
ppm: 14.55 (CH3), 15.20 (CH3), 22.06 (CH3), 22.21
(CH3), 23.22 (CH3), 23.41 (CH3), 24.27 (CH), 24.74
(CH), 39.10 (CH2), 39.33 (CH2), 40.69 (CH2), 41.03
(CH2), 44.74 (CH2), 45.34 (CH2), 62.34 (CH2), 64.24
(CH2), 67.49 (CH), 73.42 (CH), 97.09 (CH), 101.85 (CH),
110.17 (CH2=), 110.21 (CH2=), 141.08 (C). Found, %:
C 72.74; H 11.09. C12H22O2. Calculated, %: C 72.68;
H 11.18.
Ethylacetals VIIa–VIIe. To 1 mmol of aldol acetal
Va–Ve in 2 ml of ethanol (or dichloromethane) was added
at stirring 0.01 g (0.05 mmol) of p-TsOH·2H2O. On
completion of the reaction (TLC monitoring) the reaction
mixture was treated with water (10 ml), the reaction
product was extracted into dichloromethane (3 × 15 ml),
the combined extracts were dried with Na2SO4. On
removing the solvent at a reduced pressure acetals VIIa–
VIIe were isolated by column chromatography (eluent
petroleum ether–ethyl acetate, 30 : 1) as a mixture of
diastereomers.
4-Methylene-6-(2-methylprop-1-enyl)-2-ethoxy-
tetrahydro-2H-pyran (VIIa). Colorless oily fluid with
a pleasant flower odor. Yield 0.16 g (91%), isomers ratio
2 : 3. IR spectrum, ν, cm–1: 1123 (C–O), 1046 (C–O).
1H NMR spectrum, δ, ppm: 1.20 t (1.2H, CH3CH2O,
J 7.0 Hz), 1.21 t (1.8H, CH3CH2O, J 7.0 Hz), 1.67 br.s
[1.2H, CH=C(CH3)2], 1.69 br.s [1.8H, CH=C(CH3)2],
1.73 br.s [3H, CH=C(CH3)2], 2.00–2.22 m (2H,
CH2CHCH), 2.27–2.43 m (2H, CH2CHO), 3.47–3.56 m
(1H, CH3CH2O), 3.69–3.77 m (0.6H, CH3CH2O), 3.91–
3.97 m (0.4H, CH3CH2O), 4.01 d.d.d (0.4H, CH2CHO,
J1 11.0, J2 8.2, J3 2.6 Hz), 4.37 d.d (0.4H, CHOCH2,
J1 9.5, J2 2.3 Hz), 4.49 d.d.d (0.6H, CH2CHO, J1 11.3,
J2 8.7, J3 2.8 Hz), 4.76–4.80 m (1.8H, CH2CHO, CH2=),
4.94 br.s (0.4H, CH2=), 4.95 br.s (0.4H, CH2=), 5.19 d
(0.6H, CH=, J 8.5 Hz), 5.25 d (0.4H, CH=, J 7.9 Hz).
13C NMR spectrum, δ, ppm: 14.99 (CH3), 15.12 (CH3),
18.22 (CH3), 18.39 (CH3), 38.83 (CH2), 40.28 (2 CH2),
40.80 (CH2), 62.53 (CH2), 64.24 (CH2), 66.56 (CH),
72.48 (CH), 97.24 (CH), 101.50 (CH), 110.41 (2 CH2=),
125.13 (CH=), 125.30 (CH=), 135.79 (C), 136.41 (C),
140.65 (C), 142.71 (C). Found, %: C 73.49; H 10.14.
C12H20O2. Calculated, %: C 73.43; H 10.27.
4-Methylene-6-phenyl-2-ethoxytetrahydro-2H-
pyran (VIId). Colorless oily fluid. Yield 0.21 g (96%),
isomers ratio 0.6:1. IR spectrum, ν, cm–1: 1128 (C–O),
1
1058 (C–O), 1045 (C–O). H NMR spectrum, δ, ppm:
1.24 t (1.8H, CH3CH2O, J 7.1 Hz), 1.27 t (3H, CH3CH2O,
J 6.9 Hz), 2.22–2.35 m (2H, CH2CHPh, CH2CHO), 2.38–
2.59 m (4.4H, CH2CHPh, CH2CHO), 3.50–3.65 m (1.6H,
CH3CH2O), 3.72–3.79 m (0.6H, CH3CH2O), 3.98–
4.06 m (1H, CH3CH2O), 4.39 d.d (1H, OCHPh, J1 11.5,
J2 2.3 Hz), 4.54 d.d (1H, CHOCH2, J1 9.7, J2 2.6 Hz),
4.81 d.d (0.6H, OCHPh, J1 11.5, J2 2.3 Hz), 4.88–4.90 m
(3.2H, CH2=), 5.11 d (0.6H, CHOCH2, J 3.8 Hz), 7.30–
7.44 m (8H, Ph). 13C NMR spectrum, δ, ppm: 15.00
(CH3), 15.19 (CH3), 38.79 (CH2), 40.76 (CH2), 41.93
(CH2), 42.24 (CH2), 62.63 (CH2), 64.39 (CH2), 71.43
(CH), 76.99 (CH), 97.54 (CH), 102.09 (CH), 110.87 (2
CH2=), 125.80 (C2,6 arom), 126.07 (C2,6 arom), 127.45
(C4 arom), 127.56 (C4 arom), 128.27 (C3,5 arom), 128.37
(C3,5 arom), 140.61 (C1 arom), 141.56 (C1 arom), 142.00
(C), 142.52 (C). Found, %: C 77.11; H 8.24. C14H18O2.
Calculated, %: C 77.03; H 8.31.
2-[(Benzyloxy)methyl]-4-methylene-6-ethoxy-
tetrahydro-2H-pyran (VIIe). Colorless oily fluid. Yield
0.24 g (91%), isomers ratio 0.3:1. IR spectrum, ν, cm–1:
6-Isobutyl-4-methylene-2-ethoxytetrahydro-2H-
pyran (VIIc). Colorless oily fluid with a pleasant flower
odor.Yield 0.18 g (93%), isomers ratio 1.2:1. IR spectrum,
1
1126 (C–O), 1070 (C–O). H NMR spectrum, δ, ppm:
1
ν, cm–1: 1123 (C–O), 1059 (C–O). H NMR spectrum,
1.21 t (0.9H, CH3CH2O), 1.25 t (3H, CH3CH2O), 1.89–
1.95 m (0.6H, CH2CHCH2), 2.06–2.17 m (2.6H,
CH2CHCH2, CH2CHO), 2.22–2.25 m (1H, CH2CHO),
δ, ppm: 0.89 br.s [3H, CH(CH3)2], 0.91 br.s [6.6H,
CH(CH3)2], 0.92 br.s [3.6H, CH(CH3)2], 1.20 t (3.6H,
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PREPARATION OF 3-BROMOMETHYL-3-BUTENALDIETHYLACETAL
1629
2.33–2.38 m (1H, CH2CHO), 3.39–3.56 m (4.6H,
CH2OBn, CH3CH2O, CHCH2OBn), 3.60–3.68 m (0.6H,
CH3CH2O), 3.86–3.94 m (1.3H, CH3CH2O,
CHCH2OBn), 4.31 d.d (1H, CHOCH2CH3, J1 9.5,
J2 2.6 Hz), 4.47–4.55 m (2.6H, CH2Ph), 4.72 br.s (2.3H,
CHOCH2CH3, CH2=), 4.92 br.s (0.3H, CH2=), 4.93 br.s
(0.3H, CH2=), 7.19–7.29 m (6.5H, Ph). 13C NMR
spectrum, δ, ppm: 14.98 (CH3), 15.17 (CH3), 36.37
(CH2), 36.80 (CH2), 38.83 (CH2), 40.87 (CH2), 62.47
(CH2), 64.34 (CH2), 68.53 (CH), 72.87 (CH2), 73.27
(CH2), 73.43 (2 CH2), 74.50 (CH), 97.22 (CH), 100.69
(CH), 110.81 (CH2=), 110.94 (CH2=), 127.52 (C2,4,6
arom), 127.57 (C2,4,6 arom), 127.62 (C3,5 arom), 128.32
(C3,5 arom), 138.23 (2 C1 arom), 140.22 (C), 141.88 (C).
Found, %: C 73.32; H 8.34. C16H22O3. Calculated, %: C
73.25; H 8.45.
(CH3), 18.31 (CH3), 25.57 (CH3), 25.59 (CH3), 39.34
(CH2), 39.93 (CH2), 40.33 (CH2), 41.93 (CH2), 67.08
(CH), 72.76 (CH), 91.98 (CH), 95.98 (CH), 110.66
(CH2=), 111.40 (CH2=), 124.53 (CH=), 124.82 (CH=),
136.08 (C), 136.43 (C), 140.04 (C), 142.16 (C). Found,
%: C 71.46; H 9.48. C10H16O2. Calculated, %: C 71.39;
H 9.59.
4-Methylene-6-phenyltetrahydro-2H-pyran-2-ol
(VIIId). Yield 0.38 g (79%), diastereomers ratio 1:1. IR
spectrum, ν, cm–1: 3608 (OH), 3426 (OH), 1118 (C–O),
1113 (C–O), 1052 (C–O), 1047 (C–O). 1H NMR spec-
trum, δ, ppm: 2.16–2.29 m (2H, CH2CHPh), 2.34–
2.43 m (3H, CH2CHPh, CH2CHO), 2.48–2.58 m (3H,
CH2CHO), 3.16 br.s (1H, OH), 3.72 br.s (1H, OH),
4.38 d.d (1H, CHPh, J1 11.5, J2 2.3 Hz), 4.77–4.80 m
(1H, CHOH), 4.88 br.s (1H, CH2=), 4.89 br.s (1H, CH2=),
4.93 br.s (1H, CH2=), 4.97 br.s (1H, CH2=), 5.00 d.d
(1H, CHPh, J1 11.5, J2 2.6 Hz), 5.51 br.s (1H, CHOH),
7.29–7.41 m (10H, Ph). 13C NMR spectrum, δ, ppm:
39.30 (CH2), 41.90 (2CH2), 42.44 (CH2), 72.05 (CH),
77.63 (CH), 92.40 (CH), 96.59 (CH), 111.18 (CH2=),
111.87 (CH2=), 125.94 (C2 arom), 126.04 (C6 arom),
127.65 (C4 arom), 127.73 (C3 arom), 128.40 (C5 arom),
140.01 (C1 arom), 141.07 (C1 arom), 141.71 (C), 141.98
(C). Found, %: C 75.85; H 7.37. C12H14O2. Calculated,
%: C 75.76; H 7.42.
Unsaturated aldehydes VIa, VIc, VId. The
hydrolysis of cyclic acetals VIIa, VIIc, VIId was
performed with hydrobromic acid in acetone (method a)
or in a two-phase system hydrochloric acid–
dichloroethane (method b) as described above for the
hydrolysis of acyclic acetals Va, Vc, Vd. Aldehyde VIa:
yield 75%, Z/E = 1:3 (a); 70%, Z/E = 1:10 (b). Aldehyde
VIc: yield 81%, Z/E = 1:3 (a).Aldehyde VId: yield 68%,
Z/E = 1:10.
Lactols VIIIa, VIIId, VIIIe. Ethylacetals VIIa,
VIId, VIIe (2.5 mmol) were vigorously stirred at heating
with 4 ml of 50% acetic acid for 1 h. The reaction mixture
was diluted with 30 ml of dichloromethane, washed with
a saturated water solution of NaHCO3 (30 ml), and dried
with MgSO4. On removing the solvent at a reduced
pressure and on the separation of the reaction product
by column chromatography (eluent petroleum ether–ethyl
acetate, 10:1) we obtained the corresponding mixtures
of lactols diastereomers VIIIa, VIIId, VIIIe as colorless
oily fluids.
6-[(Benzyloxy)methyl]-4-methylenetetrahydro-
2H-pyran-2-ol (VIIIe). Yield 0.42 d (71%),
diastereomers ratio 1 : 1. IR spectrum, ν, cm–1: 3608
(OH), 3439 (OH), 1241 (C–O), 1094 (C–O), 1050 (C–O),
1
1012 (C–O). H NMR spectrum, δ, ppm: 1.85–2.18 m
(5H, CH2CHCH2, CH2CHOH), 2.21–2.25 m (1H,
CH2CHOH), 2.33–2.39 m (2H, CH2CHOH), 3.34 br.s
(1H, OH), 3.37–3.57 m (5H, OH, CH2OBn), 3.95 br.s
(1H, CHOH), 4.08–4.14 m (1H, CHCH2OBn), 4.45–
4.53 m (4H, CH2Ph), 4.57–4.60 m (1H, CHCH2OBn),
4.72 br.s (1H, CH2=), 4.74 br.s (1H, CH2=), 4.78 br.s
(1H, CH2=), 4.82 br.s (1H, CH2=), 5.32 br.s (1H, CHOH),
7.19–7.27 m (10H, Ph). 13C NMR spectrum, δ, ppm:
36.22 (CH2), 36.49 (CH2), 39.47 (CH2), 41.95 (CH2),
68.90 (CH), 72.68 (CH2), 72.80 (CH2), 73.34 (CH2),
73.41 (CH2), 74.46 (CH), 92.05 (CH), 96.19 (CH), 111.13
(CH2=), 111.82 (CH2=), 127.62 (C4 arom), 127.63 (C2,6
arom), 128.32 (C3,5 arom), 137.94 (2C1 arom), 139.61
(C), 141.52 (C). Found, %: C 71.84; H 7.68. C14H18O3.
Calculated, %: C 71.77; H 7.74.
4-Methylene-6-(2-methylprop-1-enyl)tetra-
hydro-2H-pyran-2-ol (VIIIa). Yield 0.33 g (78%), (iso-
mers ratio 0.7:1). IR spectrum, ν, cm–1: 3608 (OH), 1095
(C–O), 1048 (C–O). 1H NMR spectrum, δ, ppm: 1.64 br.s
[2.1H, CH=C(CH3)2], 1.66 br.s [2.1H, CH=C(CH3)2],
1.70 br.s [6H, CH=C(CH3)2], 1.97–2.11 m (3.4H,
CH2CHCH), 2.19–2.31 m (1.7H, CH2CHOH), 2.39–
2.47 m (1.7H, CH2CHOH), 3.37–3.48 m (1H, OH), 4.03–
4.14 m (1.4H, OH, CHCHO), 4.64–4.69 m (1.4H,
CHCHO, CHOH), 4.79 br.s (2H, CH2=), 4.83 br.s (0.7H,
CH2=), 4.86 br.s (0.7H, CH2=), 5.16 d [1H, CH=C(CH3)2,
J 9.2 Hz], 5.20 d [0.7H, CH=C(CH3)2, J 9.2 Hz], 5.34
br.s (1H, CHOH). 13C NMR spectrum, δ, ppm: 18.26
4-Methyl-1-[(2-methylene-4,4-diethoxybutyl)-
sulfonyl]benzene (X). To a dispersion of 6.9 g
(32.6 mmol) of sodium sulfinate dihydrate in 26 ml of
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MINEEVA, KULINKOVICH
1630
DMF was added at vigorous stirring 6.19 g (26.1 mmol)
of substituted allyl bromide I. On completion of the
reaction (TLC monitoring) the reaction mixture was
treated with water (100 ml). The organic layer was
separated, the water layer was extracted with
dichloromethane (3×30 ml), the combined organic
solutions were washed with a saturated water solution
of NaCl (50 ml), and dried with MgSO4. On removing
the solvent at a reduced pressure the reaction product
was purified by column chromatography (eluent
petroleum ether–ethyl acetate, 20:1–5:1). Yield 6.1 g
(75%). Colorless oily fluid. IR spectrum, ν, cm–1: 1326
(SO2), 1154 (SO2), 1144 (SO2), 1089 (C–O), 1061 (C–
(1H, CH3CH2O), 3.74 d.d (1H, CHSO2Tol, J1 11.3,
J2 4.1 Hz), 4.47 t (1H, OCHO, J 5.4 Hz), 4.91 t [1H,
CH=C(CH3)2, J 8.7 Hz], 5.04 br.s (1H, CH2=), 5.29 br.s
(1H, CH2=), 7.30 d (2H, H3,5 arom, J 8.2 Hz), 7.71 d
(2H, H2,6 arom, J 8.2 Hz). 13C NMR spectrum, δ, ppm:
15.12 (CH3), 15.20 (CH3), 17.76 (CH3), 21.52 (CH3),
25.55 (CH3), 26.67 (CH2), 40.27 (CH2), 60.47 (CH2),
61.33 (CH2), 69.95 (CH), 101.94 (CH), 118.98 (CH=),
120.34 (CH2=), 129.28 (C2,3,5,6 arom), 134.31 (C), 134.66
(C1 arom), 136.79 (C), 144.35 (C4 arom). Found, %:
C 66.34; H 8.41. C21H32O4S. Calculated, %: C 66.28;
H 8.48.
2-Methyl-6-methylene-8,8-diethoxyoct-2-ene
(XI), (5EZ)-2,6-dimethyl-8,8-diethoxy-2,5-octadi-
ene (XII). To 0.38 g (1 mmol) of sulfone IX dissolved in
a cooled to –78°C mixture of 4 ml of THF, 4 ml of Et2O,
and 1 ml of petroleum ether [23] was added in succession
at vigorous stirring by small pieces 0.27 g (12 mmol) of
sodium and 2.5 ml of ethanol. On completion of the
reaction (TLC monitoring) the reaction mixture was
treated with water (25 ml) and warmed to the room
temperature. The organic layer was separated, the water
layer was extracted with ethyl ether (3×15 ml), the
combined organic solutions were washed with a saturated
water solution of NaCl (25 ml), and dried with MgSO4.
On removing the solvent at a reduced pressure and on
the separation of the reaction products by column
chromatography (eluent petroleum ether–ethyl-acetate,
80:1) we obtained 0.20 g (90%) of a mixture of isomeric
acetals XI and XII as a colorless oily fluid with a pleasant
flower odor. IR spectrum, ν, cm–1: 1131 (C–O), 1118 (C–
O). 1H NMR spectrum, δ, ppm: 1.16–1.21 m (6H,
CH3CH2O), 1.60 br.s (0.6H, CH3), 1.62 br.s (1.8H, CH3),
1.68 br.s (4.2H, CH3), 1.75 br.s (0.6H, CH3), 2.06–
2.16 m (0.8H, CH2CH2CH), 2.28 d (1.2H, CCH2CH,
J 5.5 Hz), 2.34 d (0.4H, CHCH2C, J 5.9 Hz), 2.37 d
(0.4H, CCH2CH, J 5.8 Hz), 2.66–2.72 m (1.6H,
CHCH2CH), 3.45–3.53 m (2H, CH3CH2O), 3.60–
3.68 m (2H, CH3CH2O), 4.50–4.63 m (1H, OCHO),
4.83 br.s (0.4H, CH2=), 5.06–5.10 m (1H, CH=), 5.17–
5.20 m (0.8H, CH=).
1
O). H NMR spectrum, δ, ppm: 1.08 t (6H, 2CH3CH2O,
J 7 Hz), 2.34 br.s (3H, CH3Ph), 2.37 d (2H, CCH2CH,
J 5.4 Hz), 3.33–3.41 m (2H, CH3CH2O), 3.49–3.57 m
(2H, CH3CH2O), 3.80 br.s (2H, CH2SO2Tol), 4.44 t (1H,
OCHO, J 5.4 Hz), 4.77 br.s (1H, CH2=), 5.04 br.s (1H,
CH2=), 7.22 d (2H, H3,5 arom, J 8 Hz), 7.64 d (2H,
H2,6 arom, J 8 Hz). 13C NMR spectrum, δ, ppm: 15.17
(2 CH3), 21.56 (PhCH3), 39.45 (CH2), 61.45 (2 CH2),
63.00 (CH2), 102.28 (CH), 122.61 (CH2=), 128.27
(C4 arom), 128.48 (C2,6 arom), 129.54 (C3,5 arom), 133.37
(C), 144.52 (C1 arom). Found, %: C 61.54; H 7.70.
C16H24O4S. Calculated, %: C 61.51; H 7.74.
4-Methyl-4-[(1-methylene-3,3-diethoxypropyl)-
pent-3-en-1-ylsulfonyl]benzene (IX). To a solution of
0.31 g (1 mmol) of sulfone X in 10 ml of THF cooled to
–78°C was added 1.4 ml (1.5 mmol) of 1.1 M butyllithium
solution in hexane, the reaction mixture was maintained
at this temperature for 1.5 h. Then 0.15 g (1.05 mmol) of
prenyl bromide in 1 ml of THF was added, and the mixture
was stirred for 3 h at –78°C. The reaction mixture was
treated with water (15 ml), the organic layer was
separated, the water layer was extracted with ethyl ether
(3×15 ml), the combined organic solutions were washed
with a saturated water solution of NaHCO3 (10 ml), and
dried with MgSO4. On removing the solvent at a reduced
pressure the reaction product was isolated by column
chromatography (eluent petroleum ether–ethylacetate,
30:1–6:1). Yield 0.32 g (84%). Colorless oily fluid. IR
spectrum, ν, cm–1: 1364 (SO2), 1344 (SO2), 1304 (SO2),
1131 (SO2), 1105 (SO2), 1078 (C–O). 1H NMR spectrum,
δ, ppm: 1.16 t (3H, CH3CH2O, J 7 Hz), 1.17 t (3H,
CH3CH2O, J 7 Hz), 1.53 br.s [3H, CH=C(CH3)2], 1.61
br.s [3H, CH=C(CH3)2], 2.29–2.44 m (3H,
CH2CHSO2Tol, CCH2CH), 2.43 br.s (3H, CH3Ph), 2.69–
2.76 m (1H, CH2CHSO2Tol), 3.37–3.49 m (2H,
CH3CH2O), 3.51–3.58 m (1H, CH3CH2O), 3.58–3.66 m
(3E)-3,7-Dimethyl-3,6-octadienal (XIII). To
0.42 g (1.86 mmol) of the mixture of acetals XI and XII
in 2.5 ml of petroleum ether was added at vigorous stirring
1 ml of 85% formic acid. On completion of the reaction
(TLC monitoring) the reaction mixture was treated with
water (10 ml). The organic layer was separated, the water
layer was extracted with petroleum ether (3 × 10 ml),
the combined organic solutions were washed with
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PREPARATION OF 3-BROMOMETHYL-3-BUTENALDIETHYLACETAL
1631
a saturated water solution of NaHCO3 (20 ml), and dried
with Na2SO4. On removing the solvent at a reduced
pressure the reaction product was isolated by column
chromatography (eluent benzene). Yield 0.18 g (65%),
fluid with a pleasant flower odor. IR spectrum, ν, cm–1:
CH2=), 4.94 d (1H, CH2=CH, J 10.2 Hz), 5.01 d (1H,
CH2=CH, J 17.2 Hz), 5.81 d.d.t (1H, CH2=CHCH2,
J1 10.2, J2 6.6, J3 6.2 Hz). 13C NMR spectrum, δ, ppm:
15.23 (2 CH3), 31.85 (CH2), 35.84 (CH2), 40.30 (CH2),
61.03 (2 CH2), 102.13 (CH), 111.92 (CH2=), 114.48
(CH2=), 138.30 (CH=), 144.66 (C). Found, %: C 72.74;
H 11.12. C12H22O2. Calculated, %: C 72.68; H 11.18.
1
1728 (C=O), 1465 (C=C). H NMR spectrum, δ, ppm:
1.63 br.s [3H, CH=C(CH3)2], 1.69 br.s [6H,
CH=C(CH3)2, CH2CCH3], 2.75 t (2H, CHCH2CH,
J 2.5 Hz), 3.03 d (2H, CH2CHO, J 2.0 Hz), 5.09 t (1H,
CHCCH3, J 7.0 Hz), 5.29 t [1H, CH=C(CH3)2, J 6.0 Hz],
9.61 t (1H, CHO, J 2.5 Hz). 13C NMR spectrum, δ,
ppm: 16.79 (CH3), 17.63 (CH3), 25.57 (CH3), 27.24
(CH2), 54.15 (CH2), 122.20 (CH=), 126.09 (C), 129.62
(CH=), 132.07 (C), 200.35 (CO). Found, %: C 78.93;
H 10.54. C10H16O. Calculated, %: C 78.90; H 10.59.
1-Methyl-4-[3-methyl-1-(2-methylene-3,3-
diethoxybutyl)but-2-enylsulfonyl]benzene (XVI). To
a solution of 0.16 g (1.5 mmol) of diisopropylamine in
3 ml of tetrahydrofuran cooled to –50°C was added
1.5 ml (1.5 mmol) of 1M butyllithium solution in hexane,
and the mixture was warmed to –30°C. After the addition
of 0.23 g (1 mmol) of prenyl tolyl sulfone (XV) in 3 ml of
THF the reaction mixture was cooled to –78°C, 0.24 g
(1 mmol) of substituted allyl bromide I was added, and
within 1 h the mixture was warmed to –20°C. The
mixture was treated with water (10 ml), the organic layer
was separated, the water layer was extract-ed with ethyl
ether (3 × 15 ml), the combined organic solutions were
washed with a saturated water solution of NaHCO3
(20 ml), and dried with MgSO4. On removing the solvent
at a reduced pressure the reaction product was isolated
by column chromatography (eluent petroleum ether–ethyl
acetate, 15:1). Yield 0.19 g (50%). Colorless oily fluid.
Allyl-allyl coupling. To a solution of 2.37 g (10 mmol)
of substituted allyl bromide I in 20 ml of THF at –78°C
was added in succession within 10 min 0.1 g (0.5 mmol)
of CuI and 20 ml (20 mmol) of 1 M solution of allyl- or
prenylmagnesium chloride. The reaction mixture was
stirred at the same temperature for 1 h, then it was treated
with 25 ml of saturated water solution of NH4Cl, extracted
with ethyl ether (3 × 20 ml), and the combined extracts
were dried with Na2SO4. On removing the solvent at
a reduced pressure and on the separation of the reaction
product by column chromatography (eluent petroleum
ether–ethyl acetate, 80:1) we obtained hemiacetals XI
and XIV as colorless fluids with a pleasant flower odor.
1
IR spectrum, ν, cm–1: 1145 (C–O), 1086 (C–O). H NMR
spectrum, δ, ppm: 1.16 t (3H, CH3CH2O, J 6.9 Hz),
1.17 t (3H, CH3CH2O, J 6.9 Hz), 1.18 br.s [3H,
CH=C(CH3)2], 1.64 br.s [3H, CH=C(CH3)2], 2.18 d.d
(1H, CH2CHSO2Tol, J1 14.6, J2 5.9 Hz), 2.25 d.d (1H,
CH2CHSO2Tol, J1 14.6, J2 5.4 Hz), 2.35 d.d (1H,
CHCH2C, J1 14.1, J2 11.5 Hz), 2.42 br.s (3H, CH3Ph),
2.91–2.95 m (1H, CHCH2C), 3.41–3.49 m (2H,
CH3CH2O), 3.54–3.64 m (2H, CH3CH2O), 3.93 d.d.d
(1H, CH2CHSO2Tol, J1 13.3, J2 10.2, J3 3.1 Hz), 4.51 t
(1H, OCHO, J 5.6 Hz), 4.78 br.s (1H, CH2=), 4.86 br.s
(1H, CH2=), 4.88 d (1H, CH=, J 3.1 Hz), 7.29 d (2H, H3,5
arom, J 8.2 Hz), 7.68 d (2H, H2,6 arom, J 8.2 Hz). 13C NMR
spectrum, δ, ppm: 16.25 (2 CH3), 18.83 (CH3), 22.56
(CH3), 26.62 (CH3), 27.68 (CH2), 41.31 (CH2), 62.37
(CH2), 70.95 (CH), 102.97 (CH), 119.98 (CH2=), 121.41
(CH=), 130.52 (C2,6 arom), 130.77 (C3,5 arom), 135.39
(C), 137.80 (C1 arom), 142.15 (C4 arom), 149.68 (C).
Found, %: C 66.34; H 8.41. C21H32O4S. Calculated, %:
C 66.28; H 8.48.
2-Methyl-6-methylene-8,8-diethoxyoct-2-ene
(XI). Yield 2.21 g (98%). IR spectrum, ν, cm–1: 1128 (C–
O), 1059 (C–O). 1H NMR spectrum, δ, ppm: 1.19 t (6H,
2CH3CH2O, J 6.9 Hz), 1.60 br.s [3H, CH=C(CH3)2],
1.67 br.s [3H, CH=C(CH3)2], 2.04–2.12 m (4H,
CHCH2CH2), 2.34 d (2H, CHCH2C, J 5.9 Hz), 3.46–
3.52 m (2H, CH3CH2O), 3.60–3.68 m (2H, CH3CH2O),
4.61 t (1H, OCHO, J 5.9 Hz), 4.83 br.s (2H, CH2=),
5.10 t [1H, CH=C(CH3)2, J 6.7 Hz]. 13C NMR spectrum,
δ, ppm: 15.25 (2 CH3), 17.67 (CH3), 25.65 (CH3), 26.28
(CH2), 36.34 (CH2), 40.27 (CH2), 61.02 (2 CH2), 102.05
(CH), 111.65 (CH2=), 124.01 (CH=), 131.57 (C), 145.13
(C). Found, %: C 74.33; H 11.46. C14H26O2. Calculated,
%: C 74.29; H 11.59.
5-Methylene-7,7-diethoxyhept-1-ene (XIV).
Yield 1.88 g (95%). IR spectrum, ν, cm–1: 1129 (C–O),
1
1060 (C–O). H NMR spectrum, δ, ppm: 1.19 t (6H,
(4E)-2-Methyl-6-methylene-8,8-diethoxyocta-
2,4-diene (XVII). To a boiling solution of 0.90 g
(4 mmol) of prenyl tolyl sulfone (XV) in 20 ml of
anhydrous benzene was added in one portion 0.67 g
2CH3CH2O, J 7 Hz), 2.12–2.20 m (4H, CHCH2CH2),
2.34 d (2H, CHCH2C, J 5.6 Hz), 3.45–3.53 m (2H,
CH3CH2O), 3.60–3.68 m (2H, CH3CH2O), 4.60 t (1H,
OCHO, J 5.6 Hz), 4.82 br.s (1H, CH2=), 4.84 br.s (1H,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009

MINEEVA, KULINKOVICH
1632
REFERENCES
(6 mmol) of potassium tert-butylate, and after 2 min,
0.47 g (2 mmol) of substituted allyl bromide I in 2 ml of
benzene, and the reaction mixture was heated at reflux
for 2 h. After treating with water (25 ml) and extraction
with benzene (3 × 20 ml) the combined organic solutions
were washed with 15 ml of a saturated water solution of
NH4Cl, and dried with Na2SO4. The solvent was removed
at a reduced pressure; the reaction product was isolated
by column chromatography (eluent petroleum ether–ethyl
acetate, 80 : 1). Yield 0.35 g (78%). Colorless oily fluid
with a pleasant odor. IR spectrum, ν, cm–1: 1126 (C–O),
1. Mineeva, I.V. and Kulinkovich, O.G., Zh. Org. Khim., 2008,
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1
1060 (C–O). H NMR spectrum, δ, ppm: 1.20 t (6H,
2CH3CH2O, J 7.0 Hz), 1.79 br.s [3H, CH=C(CH3)2],
1.80 br.s [3H, CH=C(CH3)2], 2.57 d (2H, CCH2CH,
J 5.4 Hz), 3.47–3.54 m (2H, CH3CH2O), 3.63–3.70 m
(2H, CH3CH2O), 4.66 t (1H, OCHO, J 5.4 Hz), 5.04 br.s
(1H, CH2=), 5.07 br.s (1H, CH2=), 5.86 br.d [1H,
CH=C(CH3)2, J 11.0 Hz], 6.15 d (1H, CCHCH,
J 15.4 Hz), 6.49 d.d (1H, CHCHCH, J1 15.4, J2 11.0 Hz).
13C NMR spectrum, δ, ppm: 15.27 (2 CH3), 18.50 (CH3),
26.15 (CH3), 37.08 (CH2), 61.55 (CH2), 102.01 (CH),
116.71 (CH2=), 125.40 (CH=), 125.51 (CH=), 132.11
(CH=), 136.17 (C), 141.90 (C). Found, %: C 74.98;
H 10.72. C10H24O2. Calculated, %: C 74.95; H 10.78.
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Conversion of trienal diethylacetal XVII into
dehydrocitral VIa. To a solution of 0.44 g (2 mmol) of
trienal diethylacetal in 3 ml of acetone was added 0.05 g
(0.1 mmol) of pyridinium p-tosylate, and the mixture was
boiled for 1 h. The mixture was treated with water
(20 ml), the organic layer was separated, the water layer
was extracted with dichloromethane (3×15 ml), the
combined organic solutions were washed with a saturated
water solution of NaHCO3 (20 ml), and dried with
MgSO4. On removing the solvent the reaction product
was dissolved in 1.5 ml of ethyl ether, 0.1 ml of triethyl-
amine was added, and the mixture was left overnight at
room temperature. The reaction mixture was treated with
water (20 ml), extracted with ethyl ether (3×10 ml), the
combined organic solutions were washed with 15 ml of
a saturated water solution of NH4Cl, and dried with
Na2SO4. The solvent was removed at a reduced pressure;
the reaction product was isolated by column
chromatography (eluent petroleum ether–ethyl acetate,
45:1). Yield 0.21 g (70%), isomers ratio 10:1.
14. Bienayme, H., Tetrahedron Lett., 1994, vol. 35, p. 7383.
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Crabbe, P., J. Org. Chem., 1982, vol. 47, p. 2552.
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Tetrahedron Lett., 1977, vol. 18, p. 1181.
22. Cardillo, G., Contento, M., Sandri, S., and Panunzio, M., J.
Chem. Soc., Perkin Trans. I, 1979, p. 1729.
23. Wakefield, B.J., Organolithium methods, London:
Academic Press, 1988.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 45 No. 11 2009