Synthesis of 2-hydroxy-5-arylselanyl-benzoates by [3+3] cyclocondensation of 1,3-bis(silyloxy)-1,3-butadienes with 2-arylseleno-3-silyloxy-alk-2-en-1-ones

Article abstract of DOI:10.1080/10426507.2011.597802

Functionalized 2-hydroxy-5-arylselanyl-benzoates were prepared by formal [3+3] cyclizations of 1,3-bis(silyloxy)-1,3-butadienes with 2-arylselanyl-3- silyloxy-alk-2-en-1-ones. Taylor & Francis Group, LLC.

Full text of DOI:10.1080/10426507.2011.597802

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Phosphorus, Sulfur, and Silicon and the
Related Elements
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Synthesis of 2-Hydroxy-5-Arylselanyl-
Benzoates by [3+3] Cyclocondensation of
1,3-Bis(Silyloxy)-1,3-Butadienes with 2-
Arylseleno-3-Silyloxy-Alk-2-en-1-Ones
Mohanad Shkoor a , Olumide Fatunsin a , Abdolmajid Riahi a b
Peter Langer a b
&
a Institut für Chemie , Universität Rostock , Albert-Einstein-Str. 3a,
18059, Rostock, Germany
b Leibniz-Institut für Katalyse e. V. an der Universität Rostock ,
Albert-Einstein-Str. 29a, 18059, Rostock, Germany
Published online: 24 Aug 2011.
To cite this article: Mohanad Shkoor , Olumide Fatunsin , Abdolmajid Riahi & Peter Langer (2011)
Synthesis of 2-Hydroxy-5-Arylselanyl-Benzoates by [3+3] Cyclocondensation of 1,3-Bis(Silyloxy)-1,3-
Butadienes with 2-Arylseleno-3-Silyloxy-Alk-2-en-1-Ones, Phosphorus, Sulfur, and Silicon and the
Related Elements, 186:9, 1997-2005, DOI: 10.1080/10426507.2011.597802
To link to this article: http://dx.doi.org/10.1080/10426507.2011.597802
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Phosphorus, Sulfur, and Silicon, 186:1997–2005, 2011
Copyright ꢀC Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2011.597802
SYNTHESIS OF 2-HYDROXY-5-ARYLSELANYL-
BENZOATES BY [3+3] CYCLOCONDENSATION
OF 1,3-BIS(SILYLOXY)-1,3-BUTADIENES
WITH 2-ARYLSELENO-3-SILYLOXY-ALK-2-EN-1-ONES
Mohanad Shkoor,1 Olumide Fatunsin,1 Abdolmajid Riahi,1,2
and Peter Langer1,2
1Institut fu¨r Chemie, Universita¨t Rostock, Albert-Einstein-Str. 3a,
18059 Rostock, Germany
2Leibniz-Institut fu¨r Katalyse e. V. an der Universita¨t Rostock, Albert-Einstein-Str.
29a, 18059 Rostock, Germany
GRAPHICAL ABSTRACT
Me3SiO
R2
OSiMe3
O
OH
TiCl4
CH2Cl2
OR3
O
R2
R1
OR3
+
Me3SiO
R1
R1
SePh
R1
SePh
Abstract Functionalized 2-hydroxy-5-arylselanyl-benzoates were prepared by formal [3+3]
cyclizations of 1,3-bis(silyloxy)-1,3-butadienes with 2-arylselanyl-3-silyloxy-alk-2-en-1-ones.
Keywords Cyclizations; organoselenium compounds; silyl enol ethers
INTRODUCTION
Diaryl selenides represent biologically relevant molecules exhibiting antimicrobial,
antitumor, and antioxidant activity. They also show conductive and supraconductive proper-
ties.1 Organoselenium compounds are more unstable than organosulfur compounds. There-
fore, their synthesis is more difficult. Aliphatic organoselenium compounds are available by
reaction of selenolates with organic halides, acyl chlorides, epoxides, and enones.2 Diaryl
selenides have been prepared by reaction of selenolates with aryl halides3 and by reaction
of organolithium, organomagnesium, and organocopper compounds with diaryl diselenides
Received 23 March 2011; accepted 3 June 2011.
Financial support by the State of Mecklenburg-Vorpommern (scholarship for M. S.) is gratefully acknowl-
edged.
Address correspondence to Peter Langer, Institut fu¨r Chemie, Universita¨t Rostock, Albert-Einstein-Str. 3a,
18059 Rostock, Germany. E-mail: peter.langer@uni-rostock.de
1997

1998
M. SHKOOR ET AL.
or arylselenyl bromides.4 An alternative approach is based on a building block strategy. Ex-
amples include the [4+2] cycloaddition of 2-(phenylselanyl)-1,3-butadienes with alkenes
and alkynes.5 Recently, we have reported6 the synthesis of 5-(phenylselanyl)salicylates
by formal [3+3] cyclizations7 of 1,3-bis(silyloxy)-1,3-butadienes8 with 2-arylselanyl-3-
silyloxy-alk-2-en-1-ones. Herein, we report full details of these studies. These transforma-
tions allow a convenient synthesis of novel 2-hydroxy-5-arylseleno-benzoates that are not
readily available by other methods.9
RESULTS AND DISCUSSION
2-Phenylselanyl-1,3-diones 2a and 2b were prepared by reaction of 1a,b with se-
lenium dioxide and diphenyl diselenide in the presence of catalytic amounts of sulfuric
acid (Scheme 1). The synthesis of 2a has been previously reported.10 The silylation of 2a,b
with chlorotrimethylsilane afforded the 3-silyloxy-2-en-1-ones 3a,b. 1,3-Bis(silyloxy)-1,3-
butadienes 4a–h were prepared as previously reported.11–13
PhSeSePh
SeO2
O
O
O
O
H2SO4 (cat.)
R1
R1
R1
R1
CH2Cl2
SePh
2a,b
1a,b
10 to 20°C
Me3SiCl
C6H6, NEt3
20 °C
2a (R1 = Me): 52%
2b (R1 = Et): 47%
Me3SiO
R1
O
3a (R1 = Me): 90%
3b (R1 = Et): 91%
R1
SePh
3a,b
Scheme 1
The TiCl4-mediated cyclization of enones 3a,b with 1,3-bis(trimethylsilyloxy)-1,3-
butadienes 4a–h afforded the highly functionalized diaryl selenides 5a–j in 55%–70%
yield (Scheme 2, Table 1). The reaction was carried out in a highly concentrated solution
as it was shown earlier that this is advantageous for formal [3+3] cyclizations of 1,3-
bis(trimethylsilyloxy)-1,3-butadienes.7,11,13 The formation of the products can be explained
by reaction of 3a,b with TiCl4 to give allylic cation A. The attack of the terminal carbon
atom of the diene onto A resulted in the formation of intermediate B. The elimination of
hexamethyldisiloxane (intermediate C) and subsequent cyclization gave intermediate D.
The elimination of titanium hydroxide and aromatization resulted in the formation of the
product.
In conclusion, we have reported a new and convenient synthesis of various highly
substituted and functionalized unsymmetrical diaryl selenides based on a building block

SYNTHESIS OF 2-HYDROXY-5-ARYLSELANYL-BENZOATES
1999
Table 1 Synthesis of 5a–j
3
4
5
R1
R2
R3
% (5)a
a
a
a
a
a
a
a
a
b
b
a
b
c
d
e
a
b
c
d
e
f
g
h
i
Me
Me
Me
Me
Me
Me
Me
Me
Et
H
H
Me
Et
Bu
Hex
Hept
Oct
H
Me
(CH2)2OMe
Me
Me
Me
Me
Me
Me
59
57
68
70
69
62
62
59
56
55
f
g
h
a
b
Me
(CH2)2OMe
j
Et
H
aYields of isolated products.
Me3SiO
R2
OSiMe3
R3
O
OH
TiCl4
CH2Cl2
R2
R1
O
O
R3
4a-h
Me3SiO
O
_
R1
SePh
78 to 20 °C
14 h
+
R1
R1
SePh
5a-j
3a,b
TiCl4
H2O
_
O
O
R2
TiCl4
Me3SiO
R1
O
O
R3
OTiCl3
R1
+
R1
R1
SePh
SePh
A
D
4a
Me3SiCl
Me3SiCl
O
O
R3
Me3SiO
R2
O
R3
TiCl3
Me3SiO
R2
O
Me3SiCl
TiCl4
O
O
R1
SePh
Me3SiO
R1
SePh
R1
(Me3Si)2O
R1
B
C
Scheme 2

2000
M. SHKOOR ET AL.
approach. The products are not readily available by other methods, and their synthesis has
not yet been reported.
EXPERIMENTAL SECTION
General Comments
All solvents were dried by standard methods, and all reactions were carried out un-
der an argon atmosphere. For 1H and 13C NMR spectra, the deuterated solvents indicated
were used. Mass spectrometric (MS) data were obtained by electron ionization (EI, 70
eV), chemical ionization (CI), or electrospray ionization (ESI). For preparative scale chro-
matography, silica gel 60 (0.063–0.200 mm, 70–230 mesh) was used. The melting points
are uncorrected.
4-Phenylselanylheptane-3,5-Dione (2b)
To a dichloromethane suspension (35 mL) of selenium dioxide (1.11 g, 10.0 mmol),
diphenyl diselenide (6.24 g, 20.0 mmol), and a catalytic amount of sulfuric acid (0.1 mL, 2.0
mmol), 3,5-heptanedione (2.3 mL, 17.0 mmol) was added at 10 ◦C. The mixture was stirred
◦
for 14 h at 20 C. The reaction mixture was poured into dichloromethane (100 mL), and
the aqueous and the organic layer were separated. The latter was washed with a saturated
aqueous solution of sodium bicarbonate (20 mL), dried (sodium sulfate), and filtered, and
the filtrate was concentrated in vacuo. The residue was purified by column chromatography
(silica gel, EtOAc, heptanes) to give 2b as a yellowish oil (1.33 g, 47%). 1H NMR (300.13
3
3
MHz, CDCl3): δ = 1.02 (t, J = 7.4 Hz, 6H, 2CH3), 2.71 (q, J = 7.6 Hz, 4H, 2CH2),
3.61 (s, 1H, CH), 7.07–7.12 (m, 2H, ArH), 7.13–7.20 (m, 3H, 3CHAr). 13C NMR (75
MHz, CDCl3): δ = 13.7, 13.9 (CH3), 31.2, 31.3 (CH2), 61.4 (CH), 125.0 (CHAr), 126.6,
128.3 (2CHAr), 130.5 (CAr), 197.0, 200.0 (CO). IR (neat, cm−1): v˜ = 3069 (w), 2976 (w),
2937 (w), 2877 (w), 1695 (m), 1575 (m), 1557 (m), 1475 (m), 1458 (m), 1436 (m), 1401
(m), 1375 (m), 1337 (m), 1296 (m), 1240 (m), 1187 (m), 1156 (m), 1099 (m), 1064 (m),
1019 (m), 997 (m), 886 (w), 847 (m), 805 (m), 731 (s), 688 (s), 666 (m), 614 (w). MS (gas
chromatography [GC]-MS, 70 eV): m/z (%): 284 (M+, 43), 282 (10), 280 (22), 255 (14), 254
(11), 253 (13), 230 (23), 228 (21), 226 (14), 225 (13), 224 (14), 172 (11). High-resolution
mass spectrometry (HRMS) (EI): Calcd. for C13H16O2Se: 284.03119; found: 284.03100.
Typical Procedure for the Synthesis of Diaryl Selenides 5a–j
To a CH2Cl2 solution (5 mL) of 3a (491 mg, 1.5 mmol) and 4a (429 mg, 1.65
mmol), TiCl4 (0.18 mL, 1.6 mmol) was dropwise added at −78 ◦C. The reaction mixture
◦
was allowed to warm to 20 C during 6–12 h. After stirring for additional 2–6 h at 20
◦C, hydrochloric acid (10%, 20 mL) was added. The organic and the aqueous layers were
separated, and the latter was extracted with dichloromethane (3 × 25 mL). The combined
organic layers were dried (Na2SO4) and filtered, and the filtrate was concentrated in vacuo.
The residue was purified by chromatography (silica gel, heptanes/ethyl acetate) to give 5a
as a colorless oil (297 mg, 59%).

SYNTHESIS OF 2-HYDROXY-5-ARYLSELANYL-BENZOATES
2001
Methyl 2-Hydroxy-4,6-Dimethyl-5-Phenylselanylbenzoate (5a)
Starting with 3a (0.491 g, 1.5 mmol) and 4a (0.429 g, 1.65 mmol), 5a was isolated
after column chromatography (ethyl acetate/heptanes) as a colorless oil (0.297 g, 59%).
1H NMR (300.13 MHz, CDCl3): δ = 2.34 (s, 3H, CH3), 2.66 (s, 3H, CH3), 3.83 (s, 3H,
OCH3), 6.75 (s, 1H, CHAr), 6.94–6.98 (m, 2H, 2CHAr), 7.05–7.14 (m, 3H, 3, ArH), 10.91
(s, 1H, OH). 13C NMR (75 MHz, CDCl3): δ = 24.4, 25.7 (CH3), 52.3 (OCH3), 112.2 (CAr),
117.3 (CHAr), 123.1 (CAr), 125.5 (CHAr), 128.2, 129.2 (2CHAr), 133.4, 146.6, 151.2 (CAr),
162.4 (COH), 171.7 (CO). IR (neat, cm−1): v˜ = 3054 (w), 2950 (w), 2922 (w), 2852 (w),
1730 (w), 1689 (w), 1656 (s), 1631 (m), 1593 (m), 1475 (m), 1375 (w), 1348 (s), 1298 (s),
1223 (s), 1186 (s), 1125 (s), 1101 (s), 1064 (s), 1020 (m), 997 (m), 947 (w), 858 (w), 801
(m), 731 (s), 688 (m), 664 (m), 589 (m). MS (GC-MS, 70 eV): m/z (%): 336 (M+, 80Se,
79), 334 (M+, 78Se, 40), 333 (15), 332 (15), 306 (21), 305 (23), 304 (100), 303 (17), 302
(52), 301 (23), 300 (20), 224 (25), 196 (15), 195 (12), 168 (13), 167 (21), 165 (10), 152
(11), 119 (12), 91 (25), 77 (12), 65 (13), 51 (10). HRMS (EI): Calcd. for C16H16O3Se (M+,
80Se): 336.02592; found: 336.02594.
Methoxyethyl 2-Hydroxy-4,6-Dimethyl-5-Phenylselanylbenzoate (5b)
Starting with 3a (0.491 g, 1.5 mmol) and 4b (0.502 g, 1.65 mmol), 5b was isolated
after column c◦hromatography (ethyl acetate/heptanes) as a white solid (0.324 g, 57%),
1
m.p. = 60–62 C. H NMR (300.13 MHz, CDCl3): δ = 2.39 (s, 3H, CH3), 2.73 (s, 3H,
CH3), 3.32 (s, 3H, OCH3), 3.61–3.65 (m, 2H, CH2), 4.41–4.45 (m, 2H, CH2), 6.79 (s, 1H,
ArH), 6.95–6.98 (m, 2H, ArH), 7.01–7.10 (m, 3H, ArH), 10.57 (s, 1H, OH).13C NMR (75
MHz, CDCl3): δ = 24.5, 25.9 (CH3), 59.0 (OCH3), 64.3, 70.3 (CH2), 112.7 (CAr), 117.6
(CHAr), 123.6 (CAr), 125.7 (CHAr), 128.4, 129.3 (2 CHAr), 133.4, 147.0, 151.4 (CAr), 161.9
(COH), 170.8 (CO). IR (neat, cm−1): v˜ = 3392 (w), 3054 (w), 2923 (w), 2881 (w), 2819
(w), 1728 (w), 1654 (s), 1593 (m), 1576 (m), 1556 (m), 1475 (m), 1449 (m), 1437 (m),
1372 (m), 1342 (m), 1295 (m), 1224 (s), 1199 (m), 1187 (m), 1130 (m), 1107 (m), 1092
(m), 1064 (m), 1020 (s), 997 (m), 859 (m), 801 (m), 732 (s), 688 (m), 623 (m), 589 (m),
538 (w). MS (GC-MS, 70 eV): m/z (%): 380 (M+, 80Se, 38), 378 (M+, 78Se, 18), 306 (19),
305 (21), 304 (100), 303 (15), 302 (48), 301 (19), 300 (17), 248 (10), 224 (34), 196 (25),
195 (16), 181 (11), 168 (14), 167 (24), 165 (13), 158 (15), 155 (12), 154 (10), 153 (12),
152 (15), 148 (16), 119 (13), 91 (40), 82 (15), 80 (16), 79 (13), 78 (60), 77 (33), 76 (10), 69
(17), 67 (12), 65 (19), 59 (17), 51 (19), 50 (11), 45 (34), 44 (42), 43 (15), 41 (10). HRMS
(EI): Calcd. for C18H20O4Se (M+, 80Se): 380.05213; found: 380.05185.
Methyl 2-Hydroxy-3,4,6-Trimethyl-5-Phenylselanylbenzoate (5c)
Starting with 3a (0.491 g, 1.5 mmol) and 4c (0.453 g, 1.65 mmol), 5c was isolated
after column chromatography (ethyl acetate/heptanes) as a colorless oil (0.356 g, 68%). 1H
NMR (300.13 MHz, CDCl3): δ = 2.11 (s, 3H, CH3), 2.40 (s, 3H, CH3), 2.64 (s, 3H, CH3),
3.81 (s, 3H, OCH3), 6.89–6.96 (m, 2H, ArH), 6.98–7.06 (m, 3H, 3 ArH), 11.16 (s, 1H, OH).
13C NMR (75 MHz, CDCl3): δ = 13.1, 22.5, 24.7 (CH3), 52.4 (OCH3), 111.8, 123.6, (CAr),
125.7 (CHAr), 128.3, 129.2 (2 CHAr), 131.5, 133.8, 143.2, 148.0 (CAr), 160.5 (COH), 172.5
(CO). IR (neat, cm−1): v˜ = 3054 (w), 2950 (w), 2872 (w), 1727 (w), 1652 (s), 1576 (m),
1546 (m), 1475 (m), 1437 (s), 1377 (m), 1344 (m), 1279 (m), 1263 (m), 1235 (s), 1194 (m),
1159 (m), 1095 (m), 1067 (m), 1020 (s), 997 (m), 846 (m), 805 (m), 731 (s), 687 (m), 665

2002
M. SHKOOR ET AL.
(m), 594 (w). MS (GC-MS, 70 eV): m/z (%): 350 (M+, 80Se, 65), 348 (M+, 78Se, 34), 347
(12), 346 (11), 320 (19), 318 (100), 317 (16), 316 (48), 315 (23), 314 (18), 181 (12), 166
(10), 165 (12), 133 (12), 105 (16), 103 (10), 91 (10), 78 (10), 77 (26). HRMS (EI): Calcd.
for (M&bond;H)−: C17H17O3Se ([M&bond;H]+, 80Se): 349.03493; found: 349.03493.
Methyl 3-Ethyl-2-Hydroxy-4,6-Dimethyl-5-Phenylselanylbenzoate (5d)
Starting with 3a (0.491 g, 1.5 mmol) and 4d (0.476 g, 1.65 mmol), 5d was isolated
after column chromatography (ethyl acetate/heptanes) as a pale yellowish oil (0.381 g,
70%). 1H NMR (300.13 MHz, CDCl3): δ = 1.13 (t, 3J = 7.4 Hz, 3H, CH3), 2.41 (s, 3H,
CH3), 2.62 (s, 3H, CH3), 2.89 (q, 3J = 7.3 Hz, 2H, PhCH2), 3.83 (s, 3H, OCH3), 6.88–6.97
(m, 2H, ArH), 6.96–7.07(m, 3H, ArH), 11.17 (s, 1H, OH). 13C NMR (75 MHz, CDCl3):
δ = 13.1 (CH3), 20.7 (CH2), 21.5, 24.7 (CH3), 52.2 (OCH3), 111.9, 123.6 (CAr), 125.3
(CHAr), 128.0, 129.1 (2 CHAr), 131.5, 133.8, 143.2, 148.2 (CAr), 160.2 (COH), 172.4 (CO).
IR (neat, cm−1): v˜ = 3055 (w), 2952 (w), 2871 (w), 1726 (w), 1654 (s), 1576 (m), 1544
(w), 1475 (m), 1436 (s), 1374 (m), 1344 (m), 1274 (m), 1257 (s), 1226 (s), 1194 (m), 1158
(m), 1106 (m), 1067 (m), 1020 (m), 997 (w), 989 (w), 848 (m), 808 (m), 731 (s), 687 (m),
665 (m), 631 (w), 579 (w). MS (GC-MS, 70 eV): m/z (%): 364 (M+, 80Se, 7), 279 (13), 167
(32), 150 (11), 149 (100), 71 (12), 70 (11), 57 (16). HRMS (EI): Calcd. for C18H20O3Se
(M+, 80Se): 364.05722; found: 364.05696.
Methyl 3-Butyl-2-Hydroxy-4,6-Dimethyl-5-Phenylselanylbenzoate (5e)
Starting with 3a (0.491 g, 1.5 mmol) and 4e (0.522 g, 1.65 mmol), 5e was isolated
after column chromatography (ethyl acetate/heptanes) as a pale yellowish oil (0.405 g,
69%). 1H NMR (300.13 MHz, CDCl3): δ = 0.86 (t, 3J = 7.6 Hz, 3H, CH3), 1.18–1.21 (m,
2H, CH2), 1.37–1.40 (m, 2H, CH2), 2.48 (s, 3H, CH3), 2.54 (q, 3J = 7.5 Hz, 2H, PhCH2),
2.68 (s, 3H, CH3), 3.86 (s, 3H, OCH3), 6.86–6.96 (m, 2H, ArH), 6.97–7.10 (m, 3H, ArH),
11.15 (s, 1H, OH). 13C NMR (75 MHz, CDCl3): δ = 13.9, 21.8 (CH3), 23.1 (CH2), 24.6
(CH3), 27.2, 31.2 (CH2), 52.3 (OCH3), 111.7, 123.6 (CAr), 125.3 (CHAr), 128.0 (2CHAr),
128.5 (CAr), 129.1 (2CHAr), 133.7, 143.2, 148.5 (CAr), 160.4 (COH), 172.4 (CO). IR (neat,
cm−1): v˜ = 3056 (w), 2953 (m), 2869 (w), 1728 (m), 1654 (s), 1577(m), 1545 (w), 1494
(w), 1475 (w), 1436 (s), 1374 (m), 1350 (m), 1277 (m), 1262 (m), 1233 (s), 1194 (m),
1157 (m), 1115 (m), 1080 (w), 1055 (w), 1021 (m), 997 (w), 963 (w), 895 (m), 852 (m),
807 (s), 731 (s), 688 (m), 665 (m), 631 (w), 575 (w). MS (GC-MS, 70 eV): 392 (M+, 80Se,
1), 266 (29), 264 (65), 262 (30), 260 (10), 230 (10), 186 (13), 183 (12), 169 (14), 158
(15), 157 (37), 156 (10), 155 (22), 154 (10), 105 (17), 99 (100), 78 (23), 77 (24), 71 (52),
69 (10), 55 (14), 51 (11), 43 (71), 41 (22), 39 (10). HRMS (EI): Calcd. for C20H23O3Se
([M&bond;H]−, 80Se): 391.08189; found: 391.08163.
Methyl 3-Hexyl-2-Hydroxy-4,6-Dimethyl-5-Phenylselanylbenzoate (5f)
Starting with 3a (0.491 g, 1.5 mmol) and 4f (0.569 g, 1.65 mmol), 5f was isolated
after column chromatography (ethyl acetate/heptanes) as a yellowish oil (0.390 g, 62%). 1H
NMR (300.13 MHz, CDCl3): δ = 0.93 (t, 3J = 7.5 Hz, 3H, CH3), 1.34–1.40 (m, 6H, 3CH2),
1.50–1.55 (m, 2H, CH2), 2.61 (s, 3H, CH3), 2.78 (q, 3J = 7.4 Hz, 2H, PhCH2), 2.81 (s, 3H,
CH3), 4.00 (s, 3H, OCH3), 6.98–7.12 (m, 2H, ArH), 7.16–7.27 (m, 3H, ArH), 11.31 (s, 1H,
OH). 13C NMR (75 MHz, CDCl3): δ = 14.1, 22.0 (CH3), 22.7 (CH2), 24.8 (CH3), 27.3,

SYNTHESIS OF 2-HYDROXY-5-ARYLSELANYL-BENZOATES
2003
28.9, 30.0, 31.9, (CH2), 52.3 (OCH3), 111.9, 123.6 (CAr), 125.4 (CHAr), 128.1 (2CHAr),
128.6 (CAr), 129.2 (2CHAr), 133.8, 143.3, 148.3 (CAr), 160.2 (COH), 172.1 (CO). IR (neat,
cm−1): v˜ = 3056 (w), 2952 (m), 2923 (m), 1747 (w), 1655 (s), 1575 (m), 1541 (w), 1472
(w), 1435 (s), 1377 (m), 1347 (m), 1271 (m), 1227 (s), 1189(m), 1150 (m), 1117 (m), 1067
(w), 1056 (w), 1021 (m), 995 (w), 958 (w), 891 (m), 849 (m), 807 (s), 729 (s), 688 (m), 666
(m), 631 (w), 575 (w). HRMS (EI): Calcd. for C22H28O3Se (M+, 80Se): 420.11636; found:
420.11637.
Methyl 3-Heptyl-2-Hydroxy-4,6-Dimethyl-5-Phenylselanylbenzoate (5g)
Starting with 3a (0.491 g, 1.5 mmol) and 4g (0.592g, 1.65 mmol), 5g was isolated
after column chromatography (ethyl acetate/heptanes) as a yellowish oil (0.403 g, 62%).
3
1H NMR (300.13 MHz, CDCl3): δ = 0.95 (t, J = 7.5 Hz, 3H, CH3), 1.33–1.43 (m, 8H,
4CH2), 1.52–1.56 (m, 2H, CH2), 2.63 (s, 3H, CH3), 2.80 (q, 3J = 7.4 Hz, 2H, PhCH2), 2.84
(s, 3H, CH3), 4.01 (s, 3H, OCH3), 7.11–7.15 (m, 2H, ArH), 7.18–7.28 (m, 3H, ArH), 11.30
(s, 1H, OH). 13C NMR (75 MHz, CDCl3): δ = 14.0, 21.9 (CH3), 22.6 (CH2), 24.7 (CH3),
27.2, 28.9, 29.3, 29.9, 31.9, (CH2), 52.2 (OCH3), 111.8, 123.7 (CAr), 125.3 (CHAr), 128.0
(2CHAr), 128.5 (CAr), 129.1 (2CHAr), 133.8, 143.2, 148.4 (CAr), 160.3 (COH), 172.4 (CO).
IR (neat, cm−1): v˜ = 3056 (w), 2952 (m), 2922 (m), 1749 (w), 1655 (s), 1577 (m), 1545
(w), 1475 (w), 1437 (s), 1375 (m), 1350 (m), 1275 (m), 1229 (s), 1194 (m), 1158 (m), 1119
(m), 1067 (w), 1057 (w), 1021 (m), 997 (w), 958 (w), 895 (m), 852 (m), 807 (s), 731 (s),
688 (m), 666 (m), 631 (w), 575 (w). MS (GC-MS, 70 eV): 434 (M+, 80Se, 26), 432 (M+,
78Se, 12), 402 (17), 318 (11), 239 (11), 214 (44), 211 (12), 196 (10), 172 (11), 158 (22),
153 (12), 141 (10), 140 (10), 130 (19), 129 (80), 117 (12), 116 (100), 101 (20), 99 (11),
98 (20), 97 (17), 96 (12), 85 (37), 83 (12), 71 (60), 69 (31), 59 (11), 57 (82), 56 (12), 55
(43), 43 (62), 41 (39). HRMS (EI): Calcd. for C23H30O3Se (M+, 80Se): 434.13547; found:
434.13584.
Methyl 2-Hydroxy-4,6-Dimethyl-3-Octyl-5-Phenylselanylbenzoate (5h)
Starting with 3a (0.491 g, 1.5 mmol) and 4h (0.615 g, 1.65 mmol), 5h was isolated
after column chromatography (ethyl acetate/heptanes) as a yellowish oil (0.396 g, 59%).
1H NMR (300.13 MHz, CDCl3): δ = 0.93 (t, 3J = 7.5 Hz, 3H, CH3), 1.34–1.47 (m, 10H,
(CH2)5), 1.51–1.57 (m, 2H, CH2), 2.62 (s, 3H, CH3), 2.82 (q, 3J = 7.4 Hz, 2H, PhCH2),
2.82 (s, 3H, CH3), 4.03 (s, 3H, OCH3), 7.10–7.14 (m, 2H, ArH), 7.17–7.29 (m, 3H, ArH),
11.31 (s, 1H, OH). 13C NMR (75 MHz, CDCl3): δ = 14.1, 21.9 (CH3), 22.7 (CH2), 23.8
(CH3), 27.5, 29.0, 29.5, 29.7, 30.0, 31. 8 (CH2), 52.2 (OCH3), 111.9, 123.8 (CAr), 125.4
(CHAr), 128.0 (2CHAr), 128.6 (CAr), 129.2 (2 CHAr), 133.9, 143.2, 148.5 (CAr), 160.4
(COH), 172.5 (CO). IR (neat, cm−1): v˜ = 2952 (m), 2921 (s), 2851 (m), 1655 (s), 1577
(m), 1545 (w), 1475 (w), 1437 (s), 1375 (m), 1351 (m), 1262 (m), 1231 (s), 1194 (m), 1157
(m), 1119 (m), 1065 (w), 1053 (w), 1021 (m), 998 (w), 962 (w), 895 (m), 847 (m), 807
(s), 731 (s), 688 (m), 666 (m), 614 (w), 597 (w). MS (GC-MS, 70 eV): 448 (M+, 80Se, 48),
446 (M+, 78Se, 23), 418 (17), 416 (30), 414 (15), 401 (11), 399 (11), 371 (16), 359 (10),
329 (10), 326 (13), 325 (13), 323 (11), 318 (23), 317 (14), 316 (13), 315 (14), 292 (16),
288 (14), 287 (10), 279 (10), 260 (13), 246 (15), 245 (100), 243 (13), 239 (13), 237 (10),
197 (11), 196 (20), 195 (20). HRMS (EI): Calcd. for C24H32O3Se (M+, 80Se): 448.15162;
found: 448.15112.

2004
M. SHKOOR ET AL.
Methyl 4,6-Diethyl-2-Hydroxy-5-Phenylselanylbenzoate (5i)
Starting with 3b (0.533 g, 1.5 mmol) and 4a (0.429 g, 1.65 mmol), 5i was isolated
after column chromatography (ethyl acetate/heptanes) as a colorless oil (0.305 g, 56%).
3
1H NMR (300.13 MHz, CDCl3): δ = 0.98–1.05 (m, 6H, 2CH3), 2.69 (q, J = 7.5 Hz,
3
2H, PhCH2), 3.15 (q, J = 7.5 Hz, 2H, PhCH2), 3.84 (s, 3H, OCH3), 6.77 (s, 1H, ArH),
6.85–6.89 (m, 2H, ArH), 6.90–7.04 (m, 3H, ArH), 10.85 (s, 1H, OH).13C NMR (75 MHz,
CDCl3): δ = 14.9, 16.1 (CH3), 30.1, 31.3 (CH2), 52.5 (OCH3), 111.8 (CAr), 116.1 (CHAr),
121.6 (CAr), 125.3 (CHAr), 127.6, 129.1 (2CHAr), 134.5, 152.7, 157.0 (CAr), 162.8 (COH),
171.5 (CO). IR (neat, cm−1): v˜ = 3055 (w), 2964 (w), 2931 (w), 2871 (w), 1731 (w), 1657
(s), 1592 (m), 1577 (m), 1555 (w), 1475 (m), 1435 (m), 1347 (m), 1318 (m), 1302 (m),
1244 (m), 1216 (s), 1099 (s), 1067 (m), 1020 (m), 997 (w), 962 (w), 938 (m), 866 (m), 808
(m), 730 (s), 688 (m), 665 (w). MS (GC-MS, 70 eV): m/z (%): 364 (M+, 80Se, 63), 362
(M+, 78Se, 33), 361 (12), 360 (12), 334 (20), 333 (21), 332 (100), 331 (13), 330 (51), 329
(20), 328 (19), 252 (10), 91 (12), 77 (11). HRMS (EI): Calcd. for C18H20O3Se (M+, 80Se):
364.05722; found: 364.05772.
2-Methoxyethyl 4,6-Diethyl-2-Hydroxy-5-Phenylselanylbenzoate (5j)
Starting with 3b (0.533 g, 1.5 mmol) and 4b (0.502 g, 1.65 mmol), 5j was isolated
after column chromatography (ethyl acetate/heptanes) as a pale yellowish solid (0.336 g,
55%), mp. 73–75 ◦C. 1H NMR (300.13 MHz, CDCl3): δ = 0.91–1.01 (m, 6H, CH3), 2.63
3
3
(q, J = 7.4 Hz, 2H, PhCH2), 3.06 (q, J = 7.5 Hz, 2H, PhCH2), 3.20 (s, 3H, OCH3),
3.51–3.54 (m, 2H, CH2), 4.30–4.34 (m, 2H, CH2), 6.69 (s, 1H, ArH), 6.83–6.88 (m, 2H,
ArH), 6.88–6.97 (m, 3H, ArH), 10.39 (s, 1H, OH). 13C NMR (75 MHz, CDCl3): δ = 14.8,
16.3 (CH3), 29.7, 31.2 (CH2), 58.5 (CH3), 64.0, 69.8 (CH2), 112.5 (CAr), 116.1 (CHAr),
121.6 (CAr), 125.2 (CHAr), 127.6, 129.1 (2CHAr), 134.6, 152.8, 156.9 (CAr), 162.1 (COH),
170.3 (CO). IR (neat, cm−1): v˜ = 3399 (w), 3055 (w), 2964 (w), 2928 (w), 2872 (w), 1892
(w), 1777 (w), 1729 (m), 1656 (s), 1592 (m), 1577 (m), 1553 (w), 1475 (m), 1436 (m),
1398 (m), 1341 (m), 1298 (s), 1243 (m), 1216 (s), 1199 (s), 1185 (s), 1086 (s), 1020 (m),
998 (w), 981 (w), 867 (m), 838 (m), 808 (m), 730 (s), 688 (s), 665 (m). MS (GC-MS, 70
eV): m/z (%): 408 (M+, 80Se, 25), 330 (18), 329 (37), 328 (61), 327 (47), 326 (37), 325
(38), 324 (16), 281 (18), 253 (10), 249 (16), 248 (17), 247 (29), 207 (21), 115 (13), 91
(10), 77 (15), 75 (37). HRMS (EI): Calcd. for C20H24O4Se (M+, 80Se): 408.08343; found:
408.08384.
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