1,4-Pentadien-3-ones. A source for selenano 1,2,3-selena and thiadiazoles

Article abstract of DOI:10.1081/SCC-100106201

The 4-Selenanols (2,3) and 4-selenanones (4) were obtained by the reaction of 1,4-pentadien-3-ones (1) with sodium hydrogen selenide under different conditions. The fused 1,2,3-selenadiazoles (6) and 1,2,3-thiadiazoles (7) were prepared from 4 on oxidativ

Full text of DOI:10.1081/SCC-100106201

This article was downloaded by: [McGill University Library]
On: 30 July 2012, At: 03:16
Publisher: Taylor & Francis
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer
House, 37-41 Mortimer Street, London W1T 3JH, UK
Synthetic Communications: An International Journal
for Rapid Communication of Synthetic Organic
Chemistry
Publication details, including instructions for authors and subscription information:
http://www.tandfonline.com/loi/lsyc20
1,4-PENTADIEN-3-ONES. A SOURCE FOR SELENANO
1,2,3- SELENA AND THIADIAZOLES
D. Bhaskar Reddy a , A. Somasekhar Reddy a & V. Padmavathi a
a Department of Chemistry, Sri Venkateswara University, Tirupati, 517 502, India
Version of record first published: 22 Aug 2006
To cite this article: D. Bhaskar Reddy, A. Somasekhar Reddy & V. Padmavathi (2001): 1,4-PENTADIEN-3-ONES. A SOURCE
FOR SELENANO 1,2,3- SELENA AND THIADIAZOLES, Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 31:22, 3429-3437
To link to this article: http://dx.doi.org/10.1081/SCC-100106201
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
This article may be used for research, teaching, and private study purposes. Any substantial or systematic
reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to
anyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representation that the contents
will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses
should be independently verified with primary sources. The publisher shall not be liable for any loss, actions,
claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or
indirectly in connection with or arising out of the use of this material.

SYNTHETIC COMMUNICATIONS, 31(22), 3429–3437 (2001)
1,4-PENTADIEN-3-ONES. A
SOURCE FOR SELENANO 1,2,3-
SELENA AND THIADIAZOLES
D. Bhaskar Reddy,* A. Somasekhar Reddy,
and V. Padmavathi
Department of Chemistry, Sri Venkateswara
University, Tirupati – 517 502, India
ABSTRACT
The 4-Selenanols (2,3) and 4-selenanones (4) were obtained by
the reaction of 1,4-pentadien-3-ones (1) with sodium hydro-
gen selenide under different conditions. The fused 1,2,3-sele-
nadiazoles (6) and 1,2,3-thiadiazoles (7) were prepared from 4
on oxidative cyclization with SeO2 and Hurd–Mori reaction
with SOCl2.
In continuation of our interest on the incorporation of heteroatoms as
part of six-membered cyclic ketones which were the source for fused hetero-
cycles,1–3 we extended our studies to 4-selenanones. The present communi-
cation deals with the results obtained in such processes.
By refluxing an equimolar mixture of 1,5-diphenyl-1,4-pentadien-3-
one (1a) with sodium hydrogen selenide, generated in situ from selenium
and sodium borohydride in 1 : 2 ratio under nitrogen atmosphere and
*Corresponding author.
3429
Copyright & 2001 by Marcel Dekker, Inc.
www.dekker.com

ORDER
REPRINTS
3430
BHASKAR REDDY, SOMASEKHAR REDDY, AND PADMAVATHI
sodium acetate gave 4-selenanols (2a) and (3a) over 80% yield (Scheme).
The 2 with equatorial -OH was found to be a major product (ꢀ 70%) while
3 with axial -OH was separated as a minor one (ꢀ 15%). Repetetion of this
work with 1,5-diaryl-1,4-pentadien-3-ones 1b–d resulted only 2 as major and
3 as minor products.
Earlier, 4-selenanones were prepared by doping selenium into 1,5-
diaryl-1,4-pentadien-3-ones using hydrogen selenide, which was generated
in situ from aluminium selenide.4 This reagent was not found to be conve-
Scheme.
nient due to the poisonous character, unpleasant odour and instability.5
Furthermore, the generation of hydrogen selenide from aluminium selenide
was slow inspite of refluxing the reaction mixture for longer times.
In order to overcome these problems, sodium hydrogen selenide gen-
erated from selenium and sodium borohydride has been used. The reaction
of 1 with sodium hydrogen selenide in the presence of sodium acetate under

ORDER
REPRINTS
1,4-PENTADIEN-3-ONES
3431
nitrogen atmosphere gave a mixture of products. The latter were separated
and were identified as epimeric 4-selenanols (2 and 3) instead of the expected
4-selenanones (4) by spectral parameters. Then, the reaction was monitored
at frequent intervals to ascertain whether doping of selenium or the reduc-
tion of keto group under priority. Had it been the reduction, the resultant
1,5-diaryl-1,4-pentadien-3-ol has no conjugation and hence cyclization
would not be effective. On the other hand, if cyclization took place first,
the resultant 4-selenanone may undergo reduction with excess sodium
borohydride present in the reaction mixture, thus leading to only 4-selena-
nols. Indeed, 4-selenanone on reduction with lithium aluminium hydride
gave 4-selenanols almost in similar ratio.6,7
The configuration and conformations of 4-selenanols was assigned on
1
the basis of H NMR (Figure 1). In 2a the methine protons at C-2 and C-6
showed a doublet of doublet at 4.32 ppm. Further, two double doublets
observed at 2.58 and 2.19 were due to axial and equatorial methylene
protons at C-3 and C-5 whereas the proton at C-4 showed a multiplet in
the region 3.66–3.88 ppm. These observations are contrary to the earlier
values.6,7 The hydroxylic proton at C-4 exhibited a broad singlet at
1
1.49 ppm. On the other hand the H NMR spectrum of 3a displayed two
multiplets for methine (C-2 and C-6) and methylene (C-3 and C-5) protons
at 4.65–4.78 and at 2.18–2.36 ppm. A broad singlet at 4.20 was observed for
the proton at C-4 and the hydroxyl proton showed a multiplet in the region
1.62–1.84 ppm. Thus, the 1H NMR spectra of the epimeric 4-selenanols
indicate that an axial hydroxyl group was found to deshield the diaxial
protons at C-2 and C-6 by ꢀ 0.25–0.35 ppm.
In order to confirm the reaction process, the excess sodium boro-
hydride present in the ethanolic solution of sodium hydrogen selenide
was decomposed by adding acetaldehyde dropwise. When the resultant
sodium hydrogen selenide in ethanol was used the product obtained was
only 4-selenanone (4). The latter when subjected to reduction with sodium
borohydride gave 2 and 3 in almost same ratio as obtained from 1.
In fact the a-keto methylene functionality in 4 was primarily respon-
sible for the formation of annelated bicyclic systems. This has been accom-
plished by the oxidative cyclization of the semicarbazones of 4 (5) with
Figure 1.

ORDER
REPRINTS
3432
BHASKAR REDDY, SOMASEKHAR REDDY, AND PADMAVATHI
Figure 2.
selenium dioxide and thionyl chloride to obtain 5,7-diaryl(-4-alkyl)sele-
nano[3,4-d][1,2,3]selenadiazole/thiadiazole (6/7). The IR spectra of 6 and 7
showed absorption bands in the regions 1460–1478, 683–707 cmꢁ1 for N¼N
1
and C-Se/S groups, respectively. In the H NMR of 6a and 7a the ring
protons of selenacyclohexene moiety showed ABX splitting pattern. The
HA at C-5, HB and Hx at C-4 appeared as doublet of doublets due to
their geminal and vicinal couplings. Apart from this, a sharp singlet was
observed for the proton at C-7. This splitting pattern confirms the puckering
nature of the selenan ring when it is fused with selenadiazole or thiadiazole
moieties (Figure 2).
In the mass spectra of 6a and 7a moderate intense Mþ peaks were
observed at 404 and 357 corresponding to their chemical composition,
C17H14N2Se2 and C17H14N2SSe, respectively. In both the compounds an
ion at m/z 297 was observed which might be due to expulsion of N2 and
Se/S. The phenylacetylene radical cation (m/z 101) appeared as base peak in
both the systems.
In conclusion we have developed a one-pot reaction for the synthesis
of 4-selenanols and a new reagent for doping selenium into 1,5-diaryl-
1,4-pentadien-3-ones. The selena and thiadiazole rings were developed
on 4-selenanones by exploiting a-keto methylene group in the latter
compounds.
EXPERIMENTAL
Melting points were determined on a Mel–Temp apparatus and are
uncorrected. IR spectra (KBr disc) were recorded on a Beckmann IR-18
Spectrophotometer. NMR Spectra were recorded in CDCl3/DMSO-d6 using
200 MHz on a varian EM-360 Spectrophotometer, all chemical shifts were
reported in ppm from TMS as an internal standard. The mass spectra were
recorded on Jeol JMS-D 300 instrument at 70 eV. Elemental analyses were
obtained from RSIC, Punjab University, Chandigarh, India.

ORDER
REPRINTS
1,4-PENTADIEN-3-ONES
3433
The starting materials, 1,5-diaryl-1,4-pentadien-3-ones (1a, b) and
1,5-diaryl-2-alkyl-1,4-pentadien-3-ones (1c, d) were prepared as per the
literature procedure.2
2,6-Diaryl(-3-alkyl)-4-selenanols (2 and 3)
General procedure: To a well stirred suspension of selenium powder
(1.39 g, 12.5 mmol) in 15 mL ethanol at room temperature, sodium borohy-
dride (0.93 g, 25 mmol) in ethanol (20 mL) was added dropwise. Soon
a vigorous reaction sets in with the evolution of hydrogen gas. After few
minutes a colourless solution of sodium hydrogen selenide was formed to
which 1,5-diaryl-1,4-pentadien-3-one (15 mmol) and sodium acetate (1.0 g)
dissolved in absolute ethanol (25 mL) was added and refluxed for 2 h on a
water bath. After completion of the reaction, the solution was cooled
and kept in an ice box overnight. The solid separated was filtered and
recrystallized from a mixture of benzene and n-hexane (1 : 1). This is a
major product 2. The filtrate on concentration gave a syrupy substance
which was filtered through a column of silica gel to furnish 3.
2a: Yield 76%; m. p. 176–177ꢂC; IR nmax (cmꢁ1) 3380, 1030; 1H NMR
d: 1.49 (d, 1H, OH), 2.19 (dd, 2H, Hax-3 and 5, J ¼ 12.9 and 13.8), 2.58
(dd, 2H, Heq-3 and 5, J ¼ 3.4 and 13.8), 3.66–3.88 (m, 1H, H-4), 4.32
(dd, 2H, H-2 and 6, J ¼ 3.4 and 12.9), 7.20–7.80 (m, 10H, Harom); MS m/z
318, 316, 300, 237. 2b: Yield 64%; m. p. 205–206ꢂC; IR nmax (cmꢁ1) 3362,
1026; 1H NMR d: 1.64 (d, 1H, OH), 2.14 (dd, 2H, Hax-3 and 5, J ¼ 11.5 and
17.6), 2.58 (dd, 2H, Heq-3 and 5, J ¼ 3.8 and 17.6), 2.32 (s, 6H, CH3),
3.71–3.86 (m, 1H, H-4), 4.90 (dd, 2H, H–2 and 6, J ¼ 3.8 and 11.5),
6.95–7.55 (m, 8H, Harom). 2c: Yield 65%; m.p. 158–159ꢂC; IR nmax (cmꢁ1
)
1
3410, 1040; H NMR d: 0.84 (d, 3H, CH3), 1.68 (d, 1H, OH), 2.20 (dd, 1H,
Hax-5 , J ¼ 12.5 and 16.4), 2.65 (dd, 1H, Heq-5 J ¼ 3.6 and 16.4), 2.89 (d, 1H,
Hax-3,J ¼ 11.5), 3.75–3.82 (m, 1H, H-4), 4.19 (d, 1H, Hax-2, J ¼ 11.5), 4.85
(dd, 1H, Hax-6, J ¼ 3.6 and 12.5), 6.84–7.55 (m, 10H, Harom). 2d: Yield 69%;
m.p. 102–103ꢂC; IR nmax (cmꢁ1) 3310, 1038. 3a: Yield 11%; m.p.
130–131ꢂC; IR nmax (cmꢁ1) 3340, 1020; 1H NMR d: 1.92 (d, 1H, OH),
2.09 (dd, 2H, Hax-3 and 5, J ¼ 12.0 and 17.2), 2.58 (dd, 2H, Heq-3 and 5,
J ¼ 3.6 and 17.2), 4.41 (bs, 1H, H-4), 4.76 (dd, 2H, H-2 and 6, J ¼ 3.6 and
12.0), 7.16–7.58 (m, 10H, Harom). 3b: Yield 16%; m.p. 132–133ꢂC; IR
1
nmax (cmꢁ1) 3280, 1009; H NMR d: 1.96 (d, 1H, OH), 2.15 (s, 6H, CH3),
2.23 (dd, 2H, Hax-3 and 5, J ¼ 11.6 and 16.8), 2.60 (dd, 2H, Heq -3 and 5,
J ¼ 3.0 and 11.6), 4.39 (bs, 1H, H-4), 4.75 (dd, 2H, H-2 and 6, J ¼ 3.0 and
11.6), 7.02–7.58 (m, 8H, Harom). 3c: Yield 17%; m.p. 150–151ꢂC; IR nmax
(cmꢁ1) 3340, 1006; 3d: Yield 14%; m.p. 106–107ꢂC; IR nmax (cmꢁ1) 3340,

ORDER
REPRINTS
3434
BHASKAR REDDY, SOMASEKHAR REDDY, AND PADMAVATHI
1001; 1H NMR d: 0.66 (t, 3H, CH2-CH3), 0.75–0.91 (m, 2H, CH2-CH3), 2.20
(dd, 1H, Hax-5, J ¼ 12.0 and 16.8), 2.36 (d, 1H, OH), 2.55 (dd, 1H, Heq-5,
J ¼ 3.6 and 16.8), 2.81 (d, 1H, Hax-2, J ¼ 11.9), 4.31 (bs, 1H, H-4), 4.54
(d, 1H, Hax-2, J ¼ 11.9), 4.86 (dd, 1H, Hax-6, J ¼ 3.6 and 12.0), 7.00–7.60
(m, 10H, Harom).
2,6-Diaryl(-3-alkyl)-4-selenanone (4)
General procedure: To a colourless solution of sodium hydrogen
selenide obtained as described in the above procedure, acetaldehyde was
added dropwise while stirring in order to decompose the excess NaBH4.
A vigorous reaction sets in immediately with a slight foaming, which was
cooled to room temperature. To this, 1,5-diaryl-1,4-pentadien-3-one
(15 mmol) and sodium acetate (1.0 g) dissolved in absolute ethanol
(25 mL) was added and refluxed for 3 h on a water bath. After completion
of the reaction the solvent was removed with flash evaporator. The residue
was extracted with hot benzene, and concentrated under vacuo. The residual
portion was diluted with pet.ether (60–80ꢂC) (15 mL) and refrigerated over-
night. The solid separated was filtered off, dried and recrystallized from
pet.ether (60–80ꢂC) to yield 4.
4a: Yield 60%; m.p. 107–108ꢂC; IR nmax (cmꢁ1) 1696; 1H NMR
d: 2.56 (dd, 2H, Hax-3 and 5 ), 2.94 (dd, 2H, Heq-3 and 5), 4.16 (dd, 2H,
Hax-2 and 6). 4b: Yield 61%; m.p. 134–135ꢂC; IR nmax (cmꢁ1) 1690. 4c: Yield
64%; m.p. 121–122ꢂC; IR nmax (cmꢁ1) 1701; H NMR d: 0.95 (d, 3H,CH3),
1
2.95 (m, 1H, Hax-3), 3.16 (dd, 1H, Hax-5 J ¼ 10.4 and 16.5), 3.54 (dd, 1H,
Heq -5, J ¼ 4.6 and 16.5), 4.17 (d, 1H, H-2, J ¼ 11.0), 4.56 (dd, 1H, H-6,
J ¼ 4.6 and 10.4). 4d: Yield 65%; m.p. 101–102ꢂC; IR nmax (cmꢁ1) 1705.
Reduction of (4)
General procedure: To a well stirred slurry of sodium borohydride
(0.44 g, 12 mmol) in dry ether (25 mL) was added dropwise, a solution of
4-selenanone (4) (10 mmol) in dry ether (25 mL). The contents were stirred
at 40ꢂC for 6–8 h. After completion of the reaction the excess hydride was
carefully decomposed by the drop-wise addition of acetaldehyde. The
solvent was removed under reduced pressure. The product obtained was
separated by column chromatography to result 2 and 3.

ORDER
REPRINTS
1,4-PENTADIEN-3-ONES
4-Semicarbazono-2,6-diaryl(-3-Alkyl)selenan (5)
3435
General procedure: A mixture of semicarbazide hydrochloride (1.67 g,
15 mmol), sodium acetate (2.72 g, 20 mmol) and 4 (10 mmol) in methanol
(30 mL) was refluxed for 3 h. The solution was concentrated, cooled and
poured onto crushed ice. The semicarbazone thus formed was filtered,
washed with water and dried. It was recrystallized from ethanol.
5a: Yield 78%; m.p. 141–142ꢂC. IR nmax (cmꢁ1) 3368, 3280, 1700. 5b:
Yield 74%; m.p. 156–158ꢂC; IR nmax (cmꢁ1) 3460, 3340, 1708. 5c: Yield
71%; m.p. 148–150ꢂC; IR nmax (cmꢁ1) 3379, 3295, 1695. 5d: Yield 74%;
m.p. 171–172ꢂC; IR nmax (cmꢁ1) 3350, 3262, 1715.
5,7-Diaryl(-4-alkyl)selenano[3,4-d ]
[1,2,3] Selenadiazole (6)
General procedure: The semicarbazone 5 (5 mmol) was taken in
glacial acetic acid (15 mL) and the solution was stirred at 60–70ꢂC. After
all the solid has been dissolved, the powdered selenium dioxide (0.61 g,
5.5 mmol) was added in portions. The stirring was continued at the same
temperature until the evolution of gas ceased. After completion of the
reaction the mixture was cooled and filtered to remove precipitated
selenium. The filtrate was poured onto crushed ice and the crude
product obtained was filtered through a column of silica gel to get a pure
compound.
6a: Yield 62%; m.p. 112–114ꢂC; IR nmax (cmꢁ1) 702, 1680; 1H NMR d:
2.58 (dd, 1H, HA, J ¼ 4.6 and 10.4), 2.74 (dd, 1H, HB, J ¼ 10.4 and
16.2), 4.18 (dd, 1H, Hx, J ¼ 4.6 and 16.2), 4.58 (s, 1H, H-7), 6.80–7.66
(m, 10H, Harom); MS m/z 404, 376, 324, 297. Anal. Calcd. for
C17H14N2Se2: C, 50.50, H, 3.49, N, 6.94; Found: C, 50.65, H, 3.54,
N, 6.80. 6b: Yield 60%; m.p. 105–107ꢂC I Rnmax (cmꢁ1) 695, 1468;
1H NMR d: 2.14 (s, 6H, CH3), 2.52 (dd, 1H, H, J ¼ 4.4 and 10.5), 2.71
(dd, 1H, HB, J ¼ 10.5 and 16.3), 4.17 (dd, 1H, Hx, J ¼ 4.4 and 16.3), 4.52
(s, 1H, H-7), 7.00–7.80 (m, 8H, Harom); Anal. Calcd. for C19H18N2Se2:
C, 52.78, H, 4.19, N, 6.49; Found: C, 52.66, H, 4.25, N, 6.60. 6c: Yield
65%; m.p. 122–124ꢂC; IR nmax (cmꢁ1) 707, 1474; H NMR d: 2.20 (d, 3H,
1
CH3), 2.68–2.77 (m, 1H, H-4), 4.12 (d, 1H, H-5, J ¼ 11.1), 4.57 (s, 1H, H-7 ),
6.85–7.55 (m, 10H, Harom); Anal. Calcd. for C18H16N2Se2: C, 51.68, H, 3.85,
N, 6.71; Found: C, 51.79, H, 3.81, N, 6.85. 6d: Yield 64%; m.p. 109–111ꢂC;
IR nmax (cmꢁ1) 683, 1478.

ORDER
REPRINTS
3436
BHASKAR REDDY, SOMASEKHAR REDDY, AND PADMAVATHI
5,7-Diaryl(-4-alkyl)selenano[3,4-d ][1,2,3] Thiadiazole (7)
General procedure: The appropriate semicarbazone 5 (5 mmol) was
added portionwise to an excess of thionyl chloride (5 mL) at 0ꢂC. After
complete addition, the reaction mixture was allowed to attain the room
temperature and kept aside for another 2 h. Then dichloromethane
(25 mL) was added to the contents and the excess thionyl chloride was
decomposed with saturated sodium carbonate solution. The dichloro-
methane extract was washed with water and dried (an. Na2SO4). The solvent
was removed under vacuo. The gummy product so obtained was filtered
through a column of silica gel using ethyl acetate and hexane as eluents
to get 7.
7a: Yield 66%; m.p. 135–136ꢂC; IR nmax (cmꢁ1) 707, 1475; 1H NMR d:
2.65 (dd, 1H, HA, J ¼ 4.5 and 10.4), 2.88 (dd, 1H, HB, J ¼ 10.4 and 16.3),
4.40 (dd, 1H, Hx, J ¼ 4.5 and 16.3), 4.60 (s, 1H, H-7), 6.90–7.50 (m, 10H,
H
arom); MS m/z 357, 324, 297, 277; Anal. Calcd. for C17H14N2SSe: C, 57.13,
H, 3.95, N, 7.85; Found: C, 57.25, H, 3.89, N, 7.76. 7b: Yield 70%; m.p.
129–130ꢂC; IR nmax (cmꢁ1) 685, 1450; H NMR d: 2.20 (s, 6H, CH3), 2.59
1
(dd, 1H, HA, J ¼ 4.3 and 10.0), 2.85 (dd, 1H, HB , J ¼ 10.0 and 16.2), 4.42
(dd, 1H, Hx J ¼ 4.3 and 16.2), 4.62 (s, 1H, H-7), 7.05–7.70 (m, 8H, Harom);
Anal. Calcd. for C19H18N2SSe: C, 59.20, H, 4.70, N, 7.28; Found: C, 59.12,
H, 4.64; N, 7.16. 7c: Yield 69%; m.p. 118–119ꢂC; IR nmax (cmꢁ1) 702, 1466;
1H NMR d: 2.25 (d, 3H, CH3), 2.66–2.79 (m, 1H, H-4), 4.28 (d, 1H, H-5,
J ¼ 11.4), 4.59 (s, 1H, H-7), 6.98–7.40 (m, 10H, Harom); Anal. Calcd. for
C18H16N2SSe: C, 58.20, H, 4.34, N, 7.56; Found: C, 58.13, H, 4.40, N, 7.49.
7d: Yield 68%; m.p. 126–127ꢂC; IR nmax (cmꢁ1) 705, 1474.
ACKNOWLEDGMENT
We acknowledge the University Grants Commission, New Delhi for
providing Major Research Project to Prof. D. B. R. and V. P and Dr.
Reddy’s Research Foundation, Hyderabad for running NMR and Mass
spectra.
REFERENCES
1. Bhaskar Reddy, D.; Somasekhar Reddy, A.; Padmavathi, V.
Phosphorus, Sulfur and Silicon 1997, 122, 143.
2. Bhaskar Reddy, D.; Somasekhar Reddy, A.; Subba Reddy, N. Indian J.
Chem. 1999, 38B, 1342.

ORDER
REPRINTS
1,4-PENTADIEN-3-ONES
3437
3. Bhaskar Reddy, D.; Somasekhar Reddy, A.; Padmavathi, V.,
Heterocycl. Commun. 2000, 6, 271.
4. Lalezari, I.; Ghanbarpour, A.; Ghapgharan, F.; Naizi, F.; Jafari
Namin, R. J. Heterocycl. Chem. 1974, 11, 469.
5. Klayman, D.L.; Gunther, W.H.H. Organic Selenium Compounds, their
Chemistry and Biology, Washington, New York, 1972.
6. Nanjappan, P.; Ramalingam, K.; Satyamurthy, N.; Berlin, K.D. J. Org.
Chem. 1980, 46, 2542.
7. Nanjappan, P.; Ramalingam, K.; Melvin, D.H.; Arjunan, P.; Berlin,
K.D. J. Org. Chem. 1980, 45, 4622.
Received in the UK September 1, 1999

Request Permission or Order Reprints Instantly!
Interested in copying and sharing this article? In most cases, U.S. Copyright
Law requires that you get permission from the article’s rightsholder before
using copyrighted content.
All information and materials found in this article, including but not limited
to text, trademarks, patents, logos, graphics and images (the "Materials"), are
the copyrighted works and other forms of intellectual property of Marcel
Dekker, Inc., or its licensors. All rights not expressly granted are reserved.
Get permission to lawfully reproduce and distribute the Materials or order
reprints quickly and painlessly. Simply click on the "Request
Permission/Reprints Here" link below and follow the instructions. Visit the
U.S. Copyright Office for information on Fair Use limitations of U.S.
copyright law. Please refer to The Association of American Publishers’
(AAP) website for guidelines on Fair Use in the Classroom.
The Materials are for your personal use only and cannot be reformatted,
reposted, resold or distributed by electronic means or otherwise without
permission from Marcel Dekker, Inc. Marcel Dekker, Inc. grants you the
limited right to display the Materials only on your personal computer or
personal wireless device, and to copy and download single copies of such
Materials provided that any copyright, trademark or other notice appearing
on such Materials is also retained by, displayed, copied or downloaded as
part of the Materials and is not removed or obscured, and provided you do
not edit, modify, alter or enhance the Materials. Please refer to our Website
User Agreement for more details.
Order now!
Reprints of this article can also be ordered at
http://www.dekker.com/servlet/product/DOI/101081SCC100106201