Effect of the β-substituent with respect to the azido group on the reactivity of methyl (2E)-3-[5-(azidomethyl)-2,2-diethyl-1,3-dioxolan-4-yl]-2- methylprop-2-enoate

Article abstract of DOI:10.1134/S1070428013070154

Unlike methyl (2E)-3-[5-(azidomethyl)-2,2-diethyl-1,3-dioxolan-4-yl]-2 - methylprop-2-enoate which is stable on storage, its acyclic derivative, methyl (2E,4S,5S)-6-azido-5-hydroxy-2-methyl-4-(pent-3-yloxy) hex-2-enoate at 20 C undergoes unusual decomposition with formation of exo-methylidenepyrrolidine. Analogous transformation was also observed in the epoxide ring opening in methyl (2E)-2-methyl-4-[(S)-oxiran-2-yl]-4-(pent-3-yloxy)but-2-enoate and in the substitution reaction of ethyl 5,6-bis(methanesulfonyloxy)-2-methyl-4-(pent-3- yloxy)hex-2-enoate with azide ion. Opening of the oxirane ring in the former by the action of azide ion was accompanied by formation of oxazetidine derivative as a minor product. The major intramolecular cyclization products, 4-hydroxy- and 4-mehtanesulfonyloxypyrrolidines were converted into stable pyrrole derivatives via elimination of the leaving groups. The hydrogenation of methyl and ethyl (2E)-3-[5-(azidomethyl)-2,2-diethyl-1,3-dioxolan-4-yl]-2-methylprop-2- enoates over palladium catalyst afforded the expected reduction products.

Full text of DOI:10.1134/S1070428013070154

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 7, pp. 1047–1054. © Pleiades Publishing, Ltd., 2013.
Original Russian Text © F.A. Gimalova, G.M. Khalikova, V.A. Egorov, I.I. Fatkullina, A.G. Mustafin, M.S. Miftakhov, 2013, published in Zhurnal
Organicheskoi Khimii, 2013, Vol. 49, No. 7, pp. 1062–1069.
Effect of the β-Substituent with Respect to the Azido Group
on the Reactivity of Methyl (2E)-3-[5-(Azidomethyl)-2,2-diethyl-
1,3-dioxolan-4-yl]-2-methylprop-2-enoate
F. A. Gimalovaa, G. M. Khalikovab, V. A. Egorova, I. I. Fatkullinab,
A. G. Mustafinb, and M. S. Miftakhova
a Institute of Organic Chemistry, Ufa Research Center, Russian Academy of Sciences,
pr. Oktyabrya 71, Ufa, 450054 Bashkortostan, Russia
e-mail: bioreg@anrb.ru
b Bashkir State University, Ufa, Bashkortostan, Russia
Received April 30, 2012
Abstract—Unlike methyl (2E)-3-[5-(azidomethyl)-2,2-diethyl-1,3-dioxolan-4-yl]-2--methylprop-2-enoate
which is stable on storage, its acyclic derivative, methyl (2E,4S,5S)-6-azido-5-hydroxy-2-methyl-4-(pent-3-yl-
oxy)hex-2-enoate at 20°C undergoes unusual decomposition with formation of exo-methylidenepyrrolidine.
Analogous transformation was also observed in the epoxide ring opening in methyl (2E)-2-methyl-4-[(S)-
oxiran-2-yl]-4-(pent-3-yloxy)but-2-enoate and in the substitution reaction of ethyl 5,6-bis(methanesulfonyl-
oxy)-2-methyl-4-(pent-3-yloxy)hex-2-enoate with azide ion. Opening of the oxirane ring in the former by the
action of azide ion was accompanied by formation of oxazetidine derivative as a minor product. The major
intramolecular cyclization products, 4-hydroxy- and 4-mehtanesulfonyloxypyrrolidines were converted into
stable pyrrole derivatives via elimination of the leaving groups. The hydrogenation of methyl and ethyl
(2E)-3-[5-(azidomethyl)-2,2-diethyl-1,3-dioxolan-4-yl]-2-methylprop-2-enoates over palladium catalyst afford-
ed the expected reduction products.
DOI: 10.1134/S1070428013070154
Organic azides are popular synthons in the design
of nitrogen-containing compounds; they may be re-
garded as latent source of amines or nitrenes, may act
as 1,3-dipoles in cycloaddition reactions and nucleo-
philes, undergo rearrangements (e.g., Schmidt and
Curtius reactions), etc. [1–5]. The present article de-
scribes some reactions of previously synthesized azide
Ia [6] and structurally related compounds. The func-
tionalization character and topology of structure Ia
largely determine its synthetic potential and interest in
intramolecular transformations promoted by the azido
group therein.
Initially, with a view to estimate possible pathways
of carbocation binding by internal and external nucleo-
philes, we examined the reaction of azide Ia with
TiCl4–Et3SiH [7] (Scheme 1). It was found that the
azido group in Ia remained intact under ionic hydro-
genation conditions; the only product (compound II)
was that resulting from the reduction of carbocation
with external nucleophile (Et3SiH).
However, unlike initial compound Ia, azide II in
48 h was completely converted into pyrrolidine III
having an exocyclic double C=C bond [6]; by treat-
ment of III with acetyl chloride in pyridine we ob-
Scheme 1.
Et
Et
Me
COOMe
NH
Me
COOMe
OCHEt2
O
2'
Et3SiH, TiCl4
CH2Cl2
AcCl
pyridine
O
4'
HO
N3
4
3
2
3
2
Et2CHO
Et2CHO
Ac
N
2'
5'
5
3'
4'
1
1
N3
Me
COOMe
Me
COOMe
HO
Ia
II
III
IV
1047

GIMALOVA et al.
1048
Scheme 2.
Me
Me
COOMe
( )-IV
a
b
Et2CHO
Et2CHO
NH
II
COOMe
NH
Me
COOMe
NH
or
IV
Et2CHO
(retention of optical
activity)
HO
V
VI
tained functionalized pyrrole IV. Compound IV turned
out to be optically active. The enantiomer ratio deter-
mined with the use of europium tris[3-(trifluorometh-
ylhydroxymethylidene)-(−)-camphorate] as chiral shift
reagent was 7 :6, i.e., one of the enantiomers was
formed in excess over the other. It is seen that mole-
cule II contains two chiral centers which disappear in
the transformation of III into IV. Dehydration and
double bond migration according to path a (Scheme 2)
should led to complete loss of optical activity. Reten-
tion of optical activity is possible if the reaction takes
path b with allylic rearrangement of intermediate V or
VI. In both cases, the allylic rearrangement (hydrogen
atom transfer) is a concerted suprafacial process,
which should occur with retention of optical activity.
b without allylic rearrangement. Thus, the formation of
scalemic pyrrole IV provides an evidence in favor of
path b.
The use of azide ion as external nucleophile for
carbocations generated from epoxide VII (Scheme 3)
led to the formation of pyrrolidine III together with
an unidentified product [6]. More detailed study of this
reaction allowed us to identify new compound VIII as
a 3:2 mixture with initial epoxide VII, which cannot
be separated by chromatography on silica gel. The
acylation of that mixture and subsequent chromato-
graphic purification afforded N-acetyloxazetidine
derivative IX. Opening of the four-membered ring in
IX on heating in DMF–H2O (5:1) in the presence of
NaN3 and NH4Cl produced hydroxy acetate X whose
structure was also confirmed by oxidation to ketone
XI. Presumably, oxazetidine VIII is formed via partial
The fact that the amounts of enantiomers IV were
comparable indicated predominant contribution of path
Scheme 3.
OCHEt2
OCHEt2
NaN3, NH4Cl
EtOH–H2O, Δ
2'
O
HN
4
3
2
III
+
O
1
3'
Me
COOMe
Me
VIII
COOMe
VII
OCHEt2
OCHEt2
OCHEt2
AcCl
NaN3, NH4Cl
DMF–H2O, Δ
H2CrO4
Me2CO
pyridine
HO
O
O
VIII
N
Ac
AcO
AcO
Me
COOMe
Me
COOMe
Me
COOMe
IX
X
XI
Scheme 4.
OCHEt2
OCHEt2
H
O
O
H–
VIII
N
N
–H–
–N2
N
N
Me
COOMe
Me
COOMe
N
N
A
B
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 7 2013

EFFECT OF THE β-SUBSTITUENT WITH RESPECT TO THE AZIDO GROUP
1049
Scheme 5.
Me
COOEt
NH
Me
COOEt
NH
OCHEt2
NaN3, NH4Cl
DMF–H2O, Δ
RO
RO
Et2CHO
Et2CHO
+
Me
XII, XIII
COOEt
MeO
XIV
XV
XII, R = H; XIII, R = Ms.
Scheme 6.
Et
Et
Et
Et
O
O
(1) H2–Pd/BaSO4
(2) AcCl, pyridine
O
O
R'
Ac
N
Me
COOR
N
Me
COOMe
Et
H
H
Et
O
XVIa, XVIb, XVIIa, XVIIb
XVIII
O
Et
Et
O
N3
Me
COOR
O
PPh3, THF–H2O
Ia, Ib
Ph3P
N
Me
COOMe
XIX
Et
Et
OCHEt2
OCHEt2
O
O
HO
O
Et3SiH, TiCl4
PDC, CH2Cl2
Ac
Ac
Ac
N
Me
COOR
N
H
Me
XXa, XXb
COOR
N
H
Me
XXIa
COOMe
H
XVIIa, XVIIb
I, XVI, XVII, XX, R = Me (a), Et (b); XVI, R′ = H; XVII, R′ = Ac.
intramolecular cyclization of primary intermediate
(A→B), followed by elimination of nitrogen mole-
cule (Scheme 4).
with a view to obtain the corresponding amine (XVIa)
[8] stopped at the step of formation of iminophos-
phorane XIX. Opening of the dioxolane ring in amides
XVIIa and XVIIb under analogous reduction condi-
tions as for Ia led to hydroxy amides XXa and XXb in
good yields, whereas no intramolecular cyclization
products were detected (Scheme 6). The structure of
XX was also confirmed by the oxidation of hydroxy
ester XXa to ketone XXIa.
The reaction with sodium azide of bis-methanesul-
fonate XIII prepared from diol XII [6] gave a mixture
of pyrrolidine XIV and pyrrole XV in 37 and 38%
yield, respectively (Scheme 5).
Azides Ia and Ib were subjected to hydrogenation
over Pd/BaSO4 as catalyst. The reduction of Ib
smoothly afforded amine XVIb whose acetylation with
acetyl chloride in pyridine gave amide XVIIb. Pro-
longed hydrogenation of I may be accompanied by
partial reduction of the double bond. For example,
a mixture of XVIIa and XVIII was obtained by hydro-
genation of compound Ia and subsequent acetylation.
The reduction of azide Ia with triphenylphosphine
EXPERIMENTAL
The IR spectra were recorded on a Shimadzu IR
1
Prestige-21 spectrometer from thin films. The H and
13C NMR spectra were recorded on Bruker AM-300
1
(300.13 MHz for H and 75.47 MHz for 13C) and
Bruker Avance-500 spectrometers (500.13 MHz for 1H
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 7 2013

GIMALOVA et al.
1050
and 125.77 MHz for 13C) using tetramethylsilane as
internal reference. The optical rotations were measured
on a Perkin Elmer-341 polarimeter. The mass spectra
(electron impact, 70 eV) were obtained on a Thermo
Finnigan MAT 95XP mass spectrometer (ion source
temperature 200°C, batch inlet probe temperature
programming from 5 to 270°C at a rate of 22 deg/min).
The elemental compositions were determined on
a Euro EA 2000 CHN analyzer. The progress of
reactions was monitored by TLC on Sorbfil plates
(Russia); spots were detected by treatment with a solu-
tion of 4-methoxybenzaldehyde in ethanol acidified
with sulfuric acid, followed by heating to 120–150°C.
The products were isolated by column chromatography
on silica gel (30–60 g of sorbent per gram of sub-
strate); freshly distilled solvents were used as eluents.
All newly synthesized compounds were isolated as
oily substances.
2960, 2880, 1695, 1655, 1603, 1460, 1319, 1278,
1232, 1190, 1132, 1070, 957, 760. H NMR spectrum
1
(CDCl3), δ, ppm: 0.89 t (3H, CH3, J = 7.3 Hz), 0.91 t
(3H, CH3, J = 7.3 Hz), 1.49–1.66 m (4H, CH2), 1.84 s
(3H, CH3), 3.39 m (2H, 3″-H, NCH2), 3.68 s (3H,
OCH3), 3.84 d.d (1H, NCH2, J = 3.7, 11.1 Hz), 4.24 d
(1H, 4′-H, J = 3.9 Hz), 4.40 s (1H, 3′-H), 7.87 br.s (1H,
NH). 13C NMR spectrum (CDCl3), δC, ppm: 9.17 and
10.08 (CH3), 12.69 (CH3), 25.45 and 26.15 (CH2),
50.80 (OCH3), 53.85 (NCH2), 72.29 and 81.44 (C3′,
C4′), 82.85 (C3″), 88.24 (=CMe), 158.84 (C2′), 171.47
(C=O). Found: m/z 257.161 [M]+. C13H22O5. Calculat-
ed: M 257.1622.
Methyl 2-[1-acetyl-3-(pent-3-yloxy)-1H-pyrrol-
2-yl]propanoate (IV). A solution of 0.080 g
(0.31 mmol) of compound III in 5 ml of methylene
chloride was cooled to 0°C, 0.23 ml (2.82 mmol) of
pyridine was added, and 0.1 ml (1.40 mmol) of acetyl
chloride was added dropwise. The mixture was stirred
for 1 h and diluted with 10 ml of ethyl acetate. The
organic phase was washed with water and brine, dried
over MgSO4, and evaporated, and the residue was sub-
jected to column chromatography on silica gel using
ethyl acetate–petroleum ether (1:1) as eluent. Yield
0.044 g (50%), oily substance, [α]D20 = –13° (c =
0.1932, CHCl3). IR spectrum, ν, cm–1: 2967, 2939,
2878, 1739, 1715, 1603, 1501, 1462, 1435, 1373,
1331, 1290, 1205, 1092, 1055, 1034, 966, 943, 719,
Methyl (2Z)-2-[(3S,4S)-4-hydroxy-3-(pent-3-yl-
oxy)pyrrolidin-2-ylidene]propanoate (III). A solu-
tion of 0.029 g (0.1 mmol) of compound Ia [6] in 5 ml
of anhydrous methylene chloride was cooled to –35 to
–40°C, 0.02 ml (0.14 mmol) of triethylsilane was
added, and a solution of 0.01 ml (0.11 mmol) of TiCl4
in 0.5 ml of methylene chloride was added dropwise
under stirring, maintaining the temperature not exceed-
ing –30°C. The mixture was stirred at that temperature
until the initial compound disappeared (TLC), ice
water was quickly added, the mixture was allowed to
warm up to –5°C, the organic phase was separated, and
the aqueous phase was extracted with methylene
chloride (3×10 ml). The extracts were combined with
the organic phase, washed with brine, and dried over
MgSO4, the solvent was distilled off on a rotary evapo-
rator, and the residue was purified by flash chromatog-
raphy on silica gel using ethyl acetate–petroleum ether
(1:2) as eluent to isolate 0.017 g (60%) of unstable
methyl (2E,4S,5S)-6-azido-5-hydroxy-2-methyl-4-
1
681, 648. H NMR spectrum (CDCl3), δ, ppm: 0.92 t
(3H, CH3, J = 7.4 Hz), 0.93 t (3H, CH3, J = 7.4 Hz),
1.43 d (3H, CH3, J = 7.0 Hz), 1.60 m (4H, CH2, J =
7.4, 1.6 Hz), 2.47 s (3H, CH3CO), 3.63 s (3H, OCH3),
3.81 quint (1H, 3″-H, J = 5.8 Hz), 4.24 q (1H, 2-H, J =
7.1 Hz), 6.07 d (1H, =CH, J = 3.9 Hz), 6.89 d (1H,
=CH, J = 3.9 Hz). 13C NMR spectrum (CDCl3), δC,
ppm: 9.48 (CH3), 16.17 (CH3), 23.07 (CH3CO), 26.02
(CH2), 35.76 (C2), 51.83 (OCH3), 83.52 (C3″), 104.34
(C4′), 118.34 (C5′), 118.90 (C2′), 146.17 (C3′), 168.40
(CH3CO), 173.79 (CO2Me). Mass spectrum, m/z
(Irel, %): 266 (0.3) [M – CH3]+, 239 (3) [M – H –
CH3CO]+, 222 (0.3) [M – CO2Me]+, 211 (6) [M –
C5H10]+, 179 (4), 169 (78), 110 (100), 83 (22), 70 (4),
55 (9). Found, %: C 64.34; H 8.02; N 5.36. C15H23NO4.
Calculated, %: C 64.03; H 8.24; N 4.98.
1
(pent-3-yloxy)hex-2-enoate (II). H NMR spectrum
(acetone-d6), δ, ppm: 0.85 t (3H, CH3, J = 7.3 Hz),
0.88 t (3H, CH3, J = 7.4 Hz), 1.37–1.46 m (2H, CH2, J =
7.3 Hz), 1.48–1.56 m (2H, CH2), 1.92 d (3H, CH3, J =
1.2 Hz), 3.19 quint (1H, 3′-H, J = 6.1, 6.7 Hz), 3.30 d.d
(1H, NCH2, J = 7.3, 12.8 Hz), 3.38 d.d (1H, NCH2, J =
3.5, 12.8 Hz), 3.72 s (3H, OCH3), 3.83 m (1H, OH),
4.27 d (1H, 5-H, J = 5.5 Hz), 4.38 d.d (1H, 4-H, J =
5.5, 9.5 Hz), 6.60 d.d (1H, =CH, J = 9.4, 1.5 Hz).
Methyl (2E,4S)-2-methyl-4-(1,2-oxazetidin-4-yl)-
4-(pent-3-yloxy)but-2-enoate (VIII). Epoxide VII,
0.040 g (0.14 mmol), was dissolved in 5 ml of etha-
nol–water (5:1), 92 mg (0.16 mmol) of ammonium
chloride and 112 mg (0.16 mmol) of sodium azide
were added, and the mixture was heated for 3 h under
Compound IIa on storage in acetone-d6 solution
was completely converted into pyrrolidine III. [α]D20
=
+39.3° (c = 1.921, CHCl3). IR spectrum, ν, cm–1: 3360,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 7 2013

EFFECT OF THE β-SUBSTITUENT WITH RESPECT TO THE AZIDO GROUP
1051
reflux (TLC). The mixture was cooled, diluted with
10 ml of a 5% solution of NaHCO3, ethanol was
distilled off, and the residue was extracted with ethyl
acetate (3 × 10 ml). The extracts were combined,
washed with brine, dried over MgSO4, and evaporated,
and the residue was subjected to column chromatog-
raphy on silica gel using ethyl acetate–petroleum ether
(1:5) as eluent to isolate 0.018 g (44%) of pyrrolidine
III [6] and 0.012 g of an inseparable mixture of com-
pounds VII and VIII. IR spectrum, ν, cm–1: 3487,
2965, 2936, 2876, 2043, 1718, 1651, 1456, 1437,
1385, 1300, 1248, 1134, 1089, 1059, 959, 935, 744.
of 0.05 g (0.08 mmol) of compound IX, 0.058 g
(0.88 mmol) of sodium azide, and 0.038 g (0.70 mmol)
of ammonium chloride in 5 ml of a 5:1 DMF–H2O
mixture was stirred for 14 h at room temperature. The
mixture was diluted with ethyl acetate, the organic
phase was separated, washed with water and brine,
dried over MgSO4, and evaporated, and the residue
was subjected to column chromatography on silica gel
using ethyl acetate–petroleum ether (1:5 to 1:2) as
eluent. Yield 0.014 g (26%), [α]D20 = +14° (c = 0.3434,
CHCl3). IR spectrum, ν, cm–1: 3487, 2965, 2936, 2878,
1744, 1717, 1651, 1480, 1437, 1381, 1315, 1240,
1
1
1136, 1101, 1059, 1043, 937, 750. H NMR spectrum
Compound VIII (in a mixture with VII). H NMR
(CDCl3), δ, ppm: 0.85 t (3H, CH3, J = 7.3 Hz), 0.88 t
(3H, CH3, J = 7.5 Hz), 1.37–1.46 m (2H, CH2), 1.51–
1.55 m (2H, CH2), 1.91 d (3H, CH3, J = 1.3 Hz), 2.00 s
(3H, CH3CO), 2.86 br.s (1H, OH), 3.19 quint (1H,
3′-H, J = 5.2, 6.0 Hz), 3.72 s (3H, OCH3), 3.87 quint
(1H, 5-H, J = 5.5 Hz), 4.03 d.d (1H, OCH2, J = 6.7,
11.2 Hz), 4.17 d.d (1H, OCH2, J = 4.3, 11.3 Hz),
4.41 d.d (1H, 4-H, J = 5.2, 9.4 Hz), 6.66 d.d (1H, =CH,
J = 9.4, 1.5 Hz). 13C NMR spectrum (CDCl3), δC, ppm:
6.96 and 7.76 (CH3), 10.98 (CH3), 18.30 (CH3CO),
23.66 and 24.75 (CH2), 49.69 (OCH3), 63.38 (OCH2),
70.12 (C5), 72.76 (C4), 78.07 (C3′), 128.79 (C2), 138.00
(=CH), 165.77 (CO2Me), 168.50 (CH3CO). Mass
spectrum, m/z (Irel, %): 284 (0.5) [M – H2O]+, 215 (5)
[M – C5H11O]+, 199 (9), 183 (7), 141 (15), 129 (100),
123 (14), 97 (27), 71 (5). Found, %: C 60.05; H 8.33.
C15H26O6. Calculated, %: C 59.58; H 8.67.
spectrum (CDCl3), δ, ppm: 0.88 t (3H, CH3, J =
7.5 Hz), 0.89 t (3H, CH3, J = 7.5 Hz), 1.38–1.57 m
(4H, CH2), 1.93 d (3H, CH3, J = 1.3 Hz), 3.20 m (1H,
3″-H), 3.53 m and 3.78 m (1H each, NCH2), 3.72 s
(3H, OCH3), 4.18 m (1H, 4′-H), 4.49 d.d (1H, 4-H, J =
3.9, 9.3 Hz), 6.68 d.d (1H, =CH, J = 1.2, 9.4 Hz).
13C NMR spectrum (CDCl3), δC, ppm: 9.39 and 10.15
(CH3), 13.42 (CH3), 26.06 and 27.13 (CH2), 46.49
(NCH2), 52.15 (OCH3), 54.18 (NCH), 74.79 (C4),
74.88 (C4′), 80.57 (C3″), 131.38 (C2), 140.34 (C3),
168.14 (C=O). Mass spectrum, m/z (Irel, %): 199 (29)
[M – CH2NHOCH]+, 155 (47), 129 (100), 113 (15), 95
(45), 67 (16), 59 (12), 43 (38).
Methyl (2E)-4-[(S)-2-acetyl-1,2-oxazetidin-4-yl]-
2-methyl-4-(pent-3-yloxy)but-2-enoate (IX) was
synthesized as described above for compound IV by
acetylation of a mixture of VII with VIII and was
isolated by column chromatography on silica gel. Yield
~75%. IR spectrum, ν, cm–1: 2965, 2936, 2878, 2043,
1747, 1717, 1653, 1456, 1435, 1373, 1238, 1204,
Methyl (2E,4S)-6-acetoxy-2-methyl-5-oxo-4-
(pent-3-yloxy)hex-2-enoate (XI). A solution of
0.020 g (0.066 mmol) of compound X in 5 ml of
acetone was cooled to 0°C, and 0.13 ml (0.33 mmol)
of a 2.67 M solution of the Jones reagent was added
dropwise under stirring. The mixture was stirred until
the initial compound disappeared (TLC), and isopropyl
alcohol was added dropwise until the mixture turned
green. The mixture was filtered through a thin layer of
silica gel and evaporated, and the residue was subject-
ed to column chromatography on silica gel using ethyl
acetate–petroleum ether (1:5) as eluent. Yield 0.011 g
1
1136, 1088, 1067, 1043, 984, 962, 941, 750. H NMR
spectrum (CDCl3), δ, ppm: 0.85 t (3H, CH3, J =
7.5 Hz), 0.89 t (3H, CH3, J = 7.5 Hz), 1.39–1.56 m
(4H, CH2), 1.93 d (3H, CH3, J = 1.5 Hz), 2.06 s (3H,
CH3CO), 3.22 quint (1H, 3″-H, J = 5.4, 6.2 Hz),
3.67 d.d (1H, NCH2, J = 7.3, 11.9 Hz), 3.72 s (3H,
OCH3), 3.88 d.d (1H, NCH2, J = 4.0, 11.9 Hz),
4.59 d.d (1H, 4-H, J = 5.2, 9.3 Hz), 5.15 m (1H, 4′-H),
6.59 d.d (1H, =CH, J = 9.3, 1.6 Hz). 13C NMR spec-
trum (CDCl3), δC, ppm: 9.35 and 10.04 (CH3), 13.55
(CH3), 20.70 (CH3CO), 26.07 and 27.05 (CH2), 43.71
(NCH2), 52.26 (OCH3), 73.42 (C4′), 75.15 (C4), 81.03
(C3″), 132.49 (C2), 138.15 (=CH), 167.93 (CH3CO),
170.32 (CO2Me). Mass spectrum, m/z (Irel, %): 283
(0.05) [M – H – CH3]+, 233 (14), 199 (20), 159 (22),
129 (100), 97 (21), 83 (48).
1
(56%). H NMR spectrum (CDCl3), δ, ppm: 0.90 t
(3H, CH3, J = 7.3 Hz), 0.92 t (3H, CH3, J = 7.3 Hz),
1.50–1.57 m (4H, CH2), 1.96 d (3H, CH3, J = 1.2 Hz),
2.16 s (3H, CH3CO), 3.29 quint (1H, 3′-H, J = 5.8 Hz),
3.77 s (3H, OCH3), 4.80 d (1H, 4-H, J = 8.2 Hz),
4.94 d (1H, OCH2, J = 18.0 Hz), 5.07 d (1H, OCH2,
J = 18.0 Hz), 6.58 d.d (1H, =CH, J = 8.2, 1.2 Hz).
13C NMR spectrum (CDCl3), δC, ppm: 7.01 and 7.82
(CH3), 11.02 (CH3), 18.44 (CH3CO), 23.77 and 24.86
Methyl (2E)-(4S,5S)-6-acetoxy-5-hydroxy-2-
methyl-4-(pent-3-yloxy)hex-2-enoate (X). A mixture
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GIMALOVA et al.
1052
(CH2), 50.71 (OCH3), 65.22 (OCH2), 78.69 (C4), 82.02
(C3′), 143.88 (C2), 137.02 (=CH), 164.56 (CO2Me),
169.03 (CH3CO), 206.00 (C5). Found, %: C 60.38;
H 8.25. C15H24O6. Calculated, %: C 59.98; H 8.05.
(XIV). IR spectrum, ν, cm–1: 3360, 2960, 2880, 1695,
1655, 1603, 1460, 1319, 1278, 1232, 1190, 1132,
1
1070, 957, 760. H NMR spectrum (CDCl3), δ, ppm:
0.91 t (3H, CH3, J = 7.3 Hz), 0.93 t (3H, CH3, J =
7.3 Hz), 1.27 t (3H, CH3, J = 6.7 Hz), 1.48–1.64 m
(4H, CH2), 1.83 s (3H, CH3), 3.07 s (3H, SO2CH3),
3.50 m (1H, 3″-H), 3.67 d.d (1H, NCH2, J = 12.2 Hz),
3.93 d.d (1H, NCH2, J = 3.9, 12.2 Hz), 4.69 s (1H,
3′-H), 5.09 d (1H, 4′-H, J = 3.3 Hz), 7.89 br.s (1H, NH).
Ethyl (2E,4S,5S)-2-methyl-4-(pent-3-yloxy)-5,6-
bis(methanesulfonyloxy)hex-2-enoate (XIII). A solu-
tion of 0.1479 (0.43 mmol) of compound XII [6] in
5 ml of methylene chloride was cooled to 0°C, 0.12 ml
(0.87 mmol) of triethylamine and 0.07 ml (0.87 mmol)
of methanesulfonyl chloride were added, and the mix-
ture was stirred for 30 min at room temperature. The
organic phase was washed with water and brine, dried
over MgSO4, and evaporated, and the residue was
purified by column chromatography on silica gel using
ethyl acetate–petroleum ether (1:2) as eluent. Yield
0.142 g (78%), [α]D20 = –4.3° (c = 1.524, CHCl3). IR
spectrum, ν, cm–1: 3026, 2968, 2939, 2878, 1713,
1657, 1462, 1454, 1414, 1359, 1236, 1177, 1144,
Ethyl 2-[3-(pent-3-yloxy)-1H-pyrrol-2-yl]pro-
panoate (XV). [α]D20 = +5.2° (c = 0.3893, CHCl3). IR
spectrum, ν, cm–1: 3350, 2966, 2936, 2130, 1718,
1690, 1600, 1458, 1369, 1330, 1308, 1252, 1179,
1143, 1128, 1103, 1063, 1051, 950, 750, 690. 1H NMR
spectrum (CDCl3), δ, ppm: 0.96 t (3H, CH3, J =
7.3 Hz), 0.97 t (3H, CH3, J = 7.3 Hz), 1.26 t (3H, CH3,
J = 7.1 Hz), 1.45 d (3H, CH3, J = 7.3 Hz), 1.63 m (4H,
CH2), 3.74 quint (1H, 3″-H, J = 5.8 Hz), 3.95 q (1H,
2-H, J = 7.1 Hz), 4.15 m (2H, OCH2), 5.86 t (1H,
=CH, J = 2.8 Hz), 6.52 t (1H, =CH, J = 2.8 Hz),
8.15 br.s (1H, NH). 13C NMR spectrum (CDCl3), δC,
ppm: 9.52 (CH3), 14.13 (CH3), 19.10 (CH3), 25.99 and
26.04 (CH2), 35.19 (C2), 60.77 (OCH2), 84.19 (C3″),
99.11 (C4′), 114.45 (C5′), 115.26 (C2′), 141.98 (C3′),
175.08 (C=O). Mass spectrum, m/z (Irel, %): 254 (0.3)
[M + H]+, 213 (11) [M + H – OEt]+, 143 (100), 115 (5),
97 (36), 71 (13). Found: m/z 254.201 [M + H]+.
C14H23NO3. Calculated: [M + H]+ 254.1672.
1
1099, 1067, 972, 953, 833, 810, 752, 528. H NMR
spectrum (CDCl3), δ, ppm: 0.85 t (3H, CH3, J =
7.3 Hz), 0.89 t (3H, CH3, J = 7.3 Hz), 1.31 t (3H, CH3,
J = 7.4 Hz), 1.45–1.55 m (4H, CH2), 1.97 s (3H, CH3),
3.08 s (3H, SO2CH3), 3.11 s (3H, SO2CH3), 3.17 quint
(1H, 3′-H, J = 5.8 Hz), 4.22 m (2H, OCH2), 4.30 d.d
(1H, OCH2, J = 6.3, 11.3 Hz), 4.52 d.d (1H, OCH2, J =
1.2, 11.3 Hz), 4.57 d.d (1H, 4-H, J = 6.4, 9.8 Hz),
4.83 m (1H, 5-H), 6.46 d (1H, =CH, J = 9.4 Hz).
13C NMR spectrum (CDCl3), δC, ppm: 9.21 and 9.82
(CH3), 13.48 (CH3), 14.19 (CH3), 25.36 and 26.45
(CH2), 37.62 and 38.49 (SO2CH3), 61.23 (OCH2),
67.77 (C6), 71.91 (C4), 80.09 (C5), 80.44 (C3′), 134.27
(C2), 134.83 (C3), 166.80 (C=O). Mass spectrum, m/z
(Irel, %): 385 (1) [M – OEt]+, 343 (9) [M – C5H11O]+,
283 (4), 247 (10), 233 (10), 216 (22), 189 (10), 159
(8), 143 (100), 123 (21), 97 (23), 79 (8), 59 (13).
Reduction of compounds Ia and Ib with hydro-
gen. a. Compound Ib, 0.112 g (0.38 mmol), was
dissolved in 5 ml of ethanol, 0.112 g of the Lindlar
catalyst was added, and the mixture was stirred for 2 h
under a hydrogen pressure of 1 atm. The mixture was
filtered through a thin layer of silica gel, the sorbent
was washed with ethyl acetate, and the solvent was
evaporated. The residue was purified by column chro-
matography on silica gel using ethyl acetate–petroleum
ether (1:2) as eluent to isolate 0.079 g (78%) of ethyl
(2E)-3-(5-aminomethyl-2,2-diethyl-1,3-dioxolan-4-yl)-
2-methylprop-2-enoate (XVIb). [α]D20 = –26.0° (c =
0.773, CHCl3). IR spectrum, ν, cm–1: 3282, 2974,
2939, 2882, 1715, 1661, 1464, 1447, 1368, 1312,
1300, 1258, 1227, 1202, 1173, 1136, 1076, 1057,
Reaction of bis-methanesulfonate XIII with
sodium azide. Compound XIII, 0.281 g (0.67 mmol),
was dissolved in 6 ml of DMF–H2O (3:1), 0.145 g
(2.7 mmol) of ammonium chloride and 0.22 g
(3.38 mmol) of sodium azide were added, and the
mixture was heated for 3 h under reflux (TLC). The
mixture was cooled, diluted with water, and extracted
with ethyl acetate (3 × 10 ml). The extracts were
combined, washed with brine, dried over MgSO4, and
evaporated, and the residue was purified by column
chromatography on silica gel using ethyl acetate–
petroleum ether (1:3, 1:2, and 1:1) as eluent to isolate
0.064 g (37%) of pyrrolidine XIV and 0.062 g (38%)
of compound XV.
1
1032, 975, 935, 746. H NMR spectrum (CDCl3), δ,
ppm: 0.90 t (3H, CH3, J = 7.3 Hz), 0.91 t (3H, CH3,
J = 7.3 Hz), 1.26 t (3H, CH3, J = 7.3 Hz), 1.63–1.67 m
(4H, CH2), 1.88 d (3H, CH3, J = 1.2 Hz), 2.72 d.d (1H,
NCH2, J = 6.1, 13.15 Hz), 2.92 d.d (1H, NCH2, J =
3.05, 13.15 Hz), 3.75 m (1H, 5′-H), 4.18 m (2H,
OCH2), 4.57 t (1H, 4′-H, J = 8.9 Hz), 6.61 d.d (1H,
=CH, J = 1.2, 8.9 Hz). 13C NMR spectrum (CDCl3),
Ethyl (2Z)-2-[(3S,4S)-4-methanesulfonyloxy-3-
(pent-3-yloxy)pyrrolidin-2-ylidene]propanoate
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EFFECT OF THE β-SUBSTITUENT WITH RESPECT TO THE AZIDO GROUP
1053
δC, ppm: 8.03 and 8.16 (CH3), 13.23 (CH3), 14.21
(CH3), 30.43 and 30.50 (CH2), 42.55 (NCH2), 60.91
(OCH2), 74.75 (C4′), 82.36 (C5′), 113.48 (C2′), 132 06
(C2), 137.02 (C3), 167.31 (C=O). Mass spectrum, m/z
(Irel, %): 242 (46) [M – Et]+, 226 (23) [M – OEt]+, 213
(100) [M – 2Et]+, 185 (14), 169 (25), 157 (44), 126
(37), 111 (23), 98 (28), 83 (35), 70 (16), 57 (20).
Found, %: C 64.34; H 8.02; N 5.36. C15H23NO4. Cal-
culated, %: C 64.03; H 8.24; N 4.98.
4.12 q (1H, 4′-H, J = 7.1 Hz), 5.99 br.s (1H, NH).
13C NMR spectrum (CDCl3), δC, ppm: 8.06 and 8.13
(CH3), 18.07 (CH3), 23.27 (CH3CO), 30.56 and 30.65
(CH2), 36.64 (CH), 37.07 (C3), 40.79 (NCH2), 52.14
(OCH3), 77.32 (C4′), 79.98 (C5′), 113.94 (C2′), 170.08
(CH3CO), 176.65 (CO2Me).
Ethyl (2E)-3-[(4S,5S)-5-(acetamidomethyl)-2,2-
diethyl-1,3-dioxolan-4-yl]-2-methylprop-2-enoate
(XVIIb) was synthesized as described above for com-
pound IV from 0.045 g (0.17 mmol) of amine XVIb
and 0.06 ml (0.75 mmol) of acetyl chloride in 0.14 ml
b. Compound Ia, 0.046 g (0.16 mmol), was dis-
solved in ethanol, 0.065 g of the Lindlar catalyst was
added, and the mixture was stirred for 16 h under
a hydrogen pressure of 1 atm. The mixture was filtered
through a thin layer of silica gel, the sorbent was
washed with ethyl acetate, and the solvent was evapo-
rated. The residue (0.041 g) was dissolved in 5 ml of
methylene chloride, the solution was cooled to 0°C,
0.11 ml (1.42 mmol) of pyridine was added, and
0.05 ml (0.71 mmol) of acetyl chloride was added
dropwise. The mixture was stirred for 1 h and diluted
with ethyl acetate, the organic phase was washed with
water and brine, dried over MgSO4, and evaporated,
and the residue was subjected to column chromatog-
raphy on silica gel using ethyl acetate–petroleum ether
(1:2) to isolate 0.034 g (72%) of a mixture of com-
pounds XVIIa and XVIII. IR spectrum, ν, cm–1: 2963,
2930, 2880, 1718, 1653, 1456, 1437, 1385, 1298,
1273, 1238, 1192, 1157, 1136, 1111, 1059, 1032, 959,
914, 852, 813, 744.
(1.5 mmol) of pyridine. Yield 0.074 g (96%), [α]D20
=
–27.0° (c = 0.301, CHCl3). IR spectrum, ν, cm–1: 3289,
3082, 2974, 2939, 2882, 1722, 1651, 1556, 1537,
1462, 1435, 1371, 1269, 1229, 1199, 1175, 1138, 1085,
1
1057, 1039, 997, 932, 749. H NMR spectrum
(CDCl3), δ, ppm: 0.93 t (3H, CH3, J = 7.1 Hz), 0.95 t
(3H, CH3, J = 7.3 Hz), 1.30 t (3H, CH3, J = 7.3 Hz),
1.63–1.67 m (4H, CH2), 1.93 d (3H, CH3, J = 1.2 Hz),
2.01 s (3H, CH3CO), 3.37 d.t (1H, NCH2, J = 5.8,
14.0 Hz), 3.58 d.d.d (1H, NCH2, J = 3.6, 5.8,
14.04 Hz), 3.87 m (1H, 5′-H, J = 2.8 Hz), 4.18 q (2H,
OCH2, J = 7.0 Hz), 4.47 t (1H, 4′-H, J = 8.5 Hz),
5.82 br.s (1H, NH), 6.61 d.d (1H, =CH, J = 1.2,
8.5 Hz). 13C NMR spectrum (CDCl3), δC, ppm: 8.01
and 8.13 (CH3), 13.17 (CH3), 14.19 (CH3), 23.22
(CH3CO), 30.32 and 30.46 (CH2), 39.59 (NCH2),
60.95 (OCH2), 74.96 (C4′), 79.41 (C5′), 112.85 (C2′),
133.15 (C2), 135.73 (=CH), 169.95 (CH3CO), 176.21
(CO2Et). Mass spectrum, m/z (Irel, %): 312 (0.5)
[M – H]+, 284 (100) [M – Et]+, 213 (42), 182 (33), 157
(23), 140 (21), 126 (20), 98 (15), 57 (12). Found:
m/z 312.178 [M – H]+. C14H22NO5. Calculated:
[M – H] 312.189.
Methyl (2E)-3-[(4S,5S)-5-acetamidomethyl-2,2-
diethyl-1,3-dioxolan-4-yl]-2-methylprop-2-enoate
1
(XVIIa). H NMR spectrum (CDCl3), δ, ppm: 0.94 t
(3H, CH3, J = 7.3 Hz), 0.92 t (3H, CH3, J = 7.1 Hz),
1.59 q (4H, CH2, J = 7.3 Hz), 1.93 d (3H, CH3, J =
1.0 Hz), 2.00 s (3H, CH3CO), 3.29 d.t (1H, NCH2, J =
5.8, 14.0 Hz), 3.38 d.t (1H, NCH2, J = 5.9, 14.1 Hz),
3.76 s (3H, OCH3), 3.87 m (1H, 5-H), 4.47 t (1H, 4-H,
J = 8.6 Hz), 5.90 br.s (1H, NH), 6.59 d.d (1H, =CH,
J = 8.8, 1.0 Hz). 13C NMR spectrum (CDCl3), δC, ppm:
8.00 and 8.21 (CH3), 13.25 (CH3), 23.30 (CH3CO),
30.36 and 30.55 (CH2), 39.62 (NCH2), 51.76 (OCH3),
74.98 (C4′), 79.52 (C5′), 112.85 (C2′), 132.81 (C2),
136.27 (=CH), 167.75 (CH3CO), 170.02 (CO2Me).
Methyl (2E)-3-[(4S,5S)-5-(triphenylphosphanyli-
deneaminomethyl)-2,2-diethyl-1,3-dioxolan-4-yl]-2-
methylprop-2-enoate (XIX). Compound Ia, 0.16 g
(0.57 mmol), was dissolved in 5 ml of THF–H2O
(5:1), 0.223 g (0.86 mmol) of triphenylphosphine was
added, and the mixture was stirred for 4 h at 50°C.
Tetrahydrofuran was distilled off, the residue was
treated with ethyl acetate, the organic phase was
washed with brine, dried over MgSO4, and evaporated,
and the residue was purified by column chromatog-
raphy on silica gel using ethyl acetate–petroleum ether
Methyl 3-[(4S,5S)-5-acetamidomethyl-2,2-di-
ethyl-1,3-dioxolan-4-yl)]-2-methylpropanoate
(1:2, 1:1, 2:1) as eluent. Yield 0.15 g (52%), [α]D20
=
1
(XVIII). H NMR spectrum (CDCl3), δ, ppm: 0.87 t
–27.2° (c = 3.745, CHCl3). IR spectrum, ν, cm–1: 3053,
2972, 2939, 2882, 1718, 1680, 1460, 1437, 1375,
1354, 1313, 1259, 1227, 1190, 1176, 1163, 1121, 1078,
(6H, CH3, J = 7.3 Hz), 1.22 d (3H, CH3, J = 7.1 Hz),
1.68 m (4H, CH2), 1.96 m (2H, CH2), 1.99 s (3H,
CH3CO), 2.72 m (1H, CH, J = 7.2 Hz), 3.53–3.59 m
(2H, NCH2), 3.68 s (3H, OCH3), 3.87 m (1H, 5′-H),
1
1057, 1026, 939, 746, 721, 696, 542. H NMR spec-
trum (CDCl3), δ, ppm: 0.89 t (3H, CH3, J = 7.2 Hz),
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 49 No. 7 2013

GIMALOVA et al.
1054
0.92 t (3H, CH3, J = 7.3 Hz), 1.61–1.69 m (4H, CH2),
1.89 s (3H, CH3), 3.34 t (2H, NCH2, J = 4.3 Hz), 3.72 s
(3H, OCH3), 4.01 m (1H, 5′-H), 4.85 t (1H, 4′-H, J =
8.5 Hz), 6.67 d (1H, =CH, J = 8.6 Hz), 7.54–7.63 m
(9H, Ph), 7.70 d.d (6H, Ph, J = 7.7, 11.7 Hz). 13C NMR
spectrum (CDCl3), δC, ppm: 12.66 and 12.76 (CH3),
17.79 (CH3), 35.50 and 35.55 (CH2), 57.02 (NCH2),
56.44 (OCH3), 81.01 (C4′), 86.56 (C5′), 117.97 (C2′);
133.66, 133.82, 137.09, 138.25 (C6H5); 136.97 (=CH),
143.41 (C2), 171.0 (CO2Me). Found, %: C 71.75;
H 6.98; N 2.55; P 5.77. C31H36NO4P. Calculated, %:
C 71.93; H 7.01; N 2.71; P 5.98.
silica gel, the filtrate was evaporated, and the residue
was subjected to column chromatography on silica gel
using ethyl acetate–petroleum ether (1:1) as eluent to
isolate 0.008 g of unreacted compound XXa and
0.005 g (31%) of XXIa, [α]D20 = +32.3° (c = 0.306,
1
CHCl3). H NMR spectrum (CDCl3), δ, ppm: 0.89 t
(6H, CH3, J = 7.5 Hz), 1.50–1.56 m (4H, CH2), 1.96 d
(3H, CH3, J = 0.8 Hz), 2.04 s (3H, CH3CO), 3.25 quint
(2H, 3′-H, J = 5.7 Hz), 3.96 s (3H, OMe), 4.33 d.d
(1H, NCH2, J = 4.4, 21.1 Hz), 4.49 d.d (1H, NCH2, J =
4.6, 21.0 Hz), 4.78 d (1H, 4-H, J = 8.4 Hz), 6.14 br.s
(1H, NH), 6.55 d.d (1H, =CH, J = 1.2, 8.4 Hz).
13C NMR spectrum (CDCl3), δC, ppm: 9.26 and 9.61
(CH3), 13.58 (CH3), 23.02 (CH3CO), 25.29 and 25.96
(CH2), 46.89 (NCH2), 52.22 (OCH3), 79.60 (C4), 81.22
(C3′), 135.93 (C3), 152.20 (C2), 162.0 (CO2Me), 172.80
(CH3CO), 215.05 (C5). Mass spectrum, m/z (Irel, %):
268 (1) [M – OMe]+, 238 (6), 229 (11) [M – C5H10]+,
197 (18), 185 (50), 170 (40), 155 (44), 126 (100),
102 (84), 73 (48), 60 (9). Found, %: C 60.42;
H 8.28; N 4.55. C15H25NO5. Calculated, %: C 60.18;
H 8.42; N 4.68.
Ethyl (2E)-6-acetamido-5-hydroxy-2-methyl-4-
(pent-3-yloxy)hex-2-enoate (XXb) was synthesized
as described above for compound II from 0.148 g
(0.47 mmol) of XVIIb using 0.11 ml (0.68 mmol) of
Et3SiH and 0.06 ml (0.57 mmol) of TiCl4. Yield
0.121 g (80%), [α]D20 = +17.1° (c = 0.381, CHCl3).
1H NMR spectrum (CDCl3), δ, ppm: 0.85 t (3H, CH3,
J = 7.3 Hz), 0.88 t (3H, CH3, J = 7.6 Hz), 1.29 t (3H,
CH3, J = 7.1 Hz), 1.39–1.53 m (4H, CH2), 1.89 d (3H,
CH3, J = 1.3 Hz), 1.99 s (3H, CH3CO), 3.09–3.16 m
(3H, 3′-H, NCH2, OH), 3.51 d.d.d (1H, NCH2, J = 3.2,
6.6, 13.7 Hz), 3.67 m (1H, 5-H, J = 7.3 Hz), 4.12 d.d
(1H, 4′-H, J = 6.4, 9.6 Hz), 4.19 m (2H, OCH2, J =
7.1 Hz), 6.03 br.s (1H, NH), 6.55 d.d (1H, =CH, J =
1.2, 9.6 Hz). 13C NMR spectrum (CDCl3), δC, ppm:
9.12 and 9.80 (CH3), 13.23 (CH3), 14.13 (CH3), 23.17
(CH3CO), 25.32 and 26.46 (CH2), 41.58 (NCH2),
60.90 (OCH2), 72.57 (C5), 74.87 (C4), 79.75 (C3′),
132.31 (C2), 137.73 (C3), 167.16 (CO2Et), 170.42
(CH3CO). Mass spectrum, m/z (Irel, %): 315 (0.5) [M]+,
297 (0.5) [M – H2O]+, 270 (1) [M – OEt]+, 228 (15)
[M – C5H10O]+, 214 (82) [M – 2Et – Ac]+, 200 (6)
[M – C5H10 – OEt]+, 182 (7), 157 (23), 143 (100), 115
(21), 102 (26), 97 (34), 83 (14), 73 (9). Found:
m/z 315.200 [M]+. C16H29NO5. Calculated: M 315.205.
This study was performed under financial support
by the Russian Foundation for Basic Research (project
no. 11-03-97013-r_a-povolzh’e) and by the Ministry of
Education and Science of the Russian Federation (state
contract no. 14.740.11.0367).
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