Reaction between ortho-hydroxy aromatic aldehydes and dialkyl acetylenedicarboxylates in the presence of silica gel in solvent-free conditions

Article abstract of DOI:10.1080/00397910701545486

A two-component condensation reaction between an ortho-hydroxy aromatic aldehyde and an electron-poor acetylenic ester efficiently provides fully substituted electron-poor aryl vinyl ethers and chromenes in a one-pot reaction in the presence of silica-gel in solvent-free conditions. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/00397910701545486

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Reaction between ortho‐Hydroxy
Aromatic Aldehydes and Dialkyl
Acetylenedicarboxylates in the Presence of
Silica Gel in Solvent‐Free Conditions
Nader Noshiranzadeh a & Ali Ramazani a
a Department of Chemistry, The University of Zanjan, Zanjan, Iran
Published online: 10 Sep 2007.
To cite this article: Nader Noshiranzadeh & Ali Ramazani (2007): Reaction between ortho‐Hydroxy Aromatic
Aldehydes and Dialkyl Acetylenedicarboxylates in the Presence of Silica Gel in Solvent‐Free Conditions,
Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry,
37:18, 3181-3189
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Synthetic Communicationsw, 37: 3181–3189, 2007
Copyright # Taylor & Francis Group, LLC
ISSN 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910701545486
Reaction between ortho-Hydroxy Aromatic
Aldehydes and Dialkyl
Acetylenedicarboxylates in the Presence
of Silica Gel in Solvent-Free Conditions
Nader Noshiranzadeh and Ali Ramazani
Department of Chemistry, University of Zanjan, Zanjan Iran
Abstract: A two-component condensation reaction between an ortho-hydroxy
aromatic aldehyde and an electron-poor acetylenic ester efficiently provides fully sub-
stituted electron-poor aryl vinyl ethers and chromenes in a one-pot reaction in the
presence of silica-gel in solvent-free conditions.
Keywords: acetylenic ester, aryl vinyl ether, chromene, silica-gel, solvent-free
conditions
1
INTRODUCTION
Environmentally friendly syntheses of organic compounds without use of
organic solvents has improved in recent years.[1] Organic reactions using con-
ventional organic solvents, especially chlorinated hydrocarbons, pose a
serious threat to the environment because of their toxicity and volatile
nature.[1] In this regard, solvent-free catalytic organic reactions have
received tremendous attention in recent times.[2]
For several years, acetylenic esters have been attracting the attention of
organic chemists.[3] Acetylenic esters are reactive systems and take part in
many chemical syntheses.[3] The compounds almost act as Michael
acceptors in organic reactions.[4] In recent years, there have been increased
Received in the U.K. November 7, 2006
Address correspondence to Ali Ramazani, Department of Chemistry, The
University of Zanjan, P. O. Box 45195-313, Zanjan, Iran. E-mail: aliramazani@
yahoo.com
3181

3182
N. Noshiranzadeh and A. Ramazani
interest in the applications of acetylenic esters in multicomponent[5–9]
synthesis. Because of the atom economy, convergent character, and simplicity
of one-pot procedures, multicomponent condensation reactions (MCRs) have
an advantageous position among other reactions. The discovery and develop-
ment of novel MCRs are receiving growing interest from industrial chemistry
research groups and represent a new challenge for organic chemists and to the
basic understanding of organic chemistry itself.[10]
Silica gel as an additive promotes many condensation reactions in
solvent-free conditions.[11,12] Continuing our interest in solvent-free
synthesis,[13] herein we report on a hitherto unknown two-component
reaction, which, starting from simple and readily available precursors,
affords fully functionalized electron-poor aryl vinyl ethers and chromenes
in a one-pot reaction in the presence of silica-gel powder in solvent-free con-
ditions (Schemes 1, and 2 and Table 1).
2
RESULTS AND DISCUSSION
The ortho-hydroxy aromatic aldehyde 1 (or 6) and dialkyl acetylenedicarbox-
ylate 2 in the presence of silica-gel powder undergo a smooth 1 : 1 addition
reaction in solvent-free conditions at 908C in 45 min to produce compounds
3, 4, and 5 (or 7, 8, and 9) (Schemes 1, and 2 and Table 1). The reaction
proceeds smoothly and cleanly under mild conditions, and no side reactions
Scheme 1.

Reaction between Ortho-Hydroxy Aromatic Aldehydes
3183
Scheme 2.
were observed. In the absence of the silica-gel powder, the compound 1 (or 6)
was not reacted under reaction (908C, 45 min) conditions in the solvent-free
system. The reaction also did not occur in dichloromethane solutions after
several days. Thin-layer chromatography (TLC) indicated the formation of
compounds 3, 4, and 5 (or 7, 8, and 9) on the silica-gel surface. Compounds
4 (or 8) are not stable and rearranged to chromenes 5 (or 9) as a result of
staying at room temperature in solvent (CHCl3), neat or on the silica-gel
surface. The conversion of compounds 4 (or 8) to chromenes 5 (or 9) is
fairly fast in CHCl3 (or CDCl3) solution, and it was completed in less than
Table 1. Synthesis of electron-poor aryl vinyl ethers and chromenes in the presence
of silica gel in solvent-free conditions
Entry
Product
Isolated yield %
Ratio of Z/E
1a
1b
2a
2b
3a
3b
4a
4b
5a
5b
3a
5a
3b
5b
3c
5c
7a
9a
7b
9b
54
41
50
45
55
40
50
46
55
40
87/13
—
86/14
—
88/12
—
80/20
—
83/17
—

3184
N. Noshiranzadeh and A. Ramazani
20 min. In the other cases (silica-gel surface, neat and in solvents of CH2Cl2,
ethyl acetate, and petroleum ether), the conversion is very slow and was not
completed after several days. These results show that the chromenes 5 (or
9) are more stable than the compounds 4 (or 8). The presence of an
anomeric effect[14] in the chromenes 5 (or 9) may be factor in increasing
the thermodynamic stability of the chromenes 5 (or 9) relative to
compounds 4 (or 8). We have not investigated the roll of CHCl3 (or CDCl3)
solution in the fast conversion of the compounds 4 (or 8) to the chromenes
5 (or 9). It seems that the presence of trace amounts of HCl (or DCl) in the
CHCl3 (or CDCl3) solution may be the factor as an acid catalyst in increasing
the conversion rate. In the case of the mixture of compounds 4a and 5a, we
1
prepared the H NMR (CDCl3) spectrum. The chemical shifts (dH) for 4a
[(3.82 and 3.90 (6H, 2 s, 2 OCH3); 5.74 (1H, s, CH of CHOH); 5.75 (1H, s,
OH); 6.98–7.41 (4H, m, arom.)] and 5a [(3.86 and 3.95 (6H, 2 s, 2 OCH3);
5.11 (1H, s, exchanged by D2O addition, OH); 6.98–7.41 (4H, m, arom.);
7.81 (1 H, s, 55CH)] were assigned from the spectra. The relative population
1
of 4a/5a (40:60) was estimated based on H NMR (CDCl3) spectrum of the
mixture. About after 15 min, the compound 4a was completely converted to
1
5a in CDCl3 solution at room temperature, and in the H NMR (CDCl3)
1
spectrum, signals of only 5a were observed. The H NMR (CDCl3) spectra
of compounds 3 (or 7) show the presence of two stereoisomers (E and Z)
for each O-vinyl ether. The relative population of E and Z isomers were
determined via their 1H NMR spectra (see Table 1 and Experimental section).
The mechanism of the reaction between the ortho-hydroxy aromatic
aldehyde 1 (or 6) and dialkyl acetylenedicarboxylate 2 in the presence of
silica-gel powder in solvent-free conditions has not been established exper-
imentally. However, in some preliminary investigations, we examined the
conversion of compounds 3 (or 7) to the chromenes 5 (or 9) in the reaction
conditions. We observed that compounds 3 (or 7) are stable in the reaction
conditions, and therefore another pathway may be exist for the formation of
chromenes 5 (or 9) (Schemes 1, and 2 and Table 1).
1
The structures of the products were deduced from their IR, H NMR,
and 13C NMR spectra. The mass spectra of these compounds displayed
molecular ion peaks at the appropriate m/z values (See Experimental
section).
3
CONCLUSIONS
We believe the reported method offers a mild, simple, and efficient route for
the preparation of substituted electron-poor aryl vinyl ethers and chromenes.
Its ease of workup, high yields, and fairly short reaction times make it a useful
addition to modern synthetic methodologies. Other aspects of this process are
under investigation.

Reaction between Ortho-Hydroxy Aromatic Aldehydes
EXPERIMENTAL
3185
4
Starting materials and solvents were obtained from Merck (Germany) and
Fluka (Switzerland) and were used without further purification. Flash-
chromatography columns were prepared from Merck silica-gel powder.
Melting points were measured on an Electrothermal 9100 apparatus and are
uncorrected. Elemental analyses for C and H were performed using a
Heraeus CHN-O-Rapid analyzer. IR spectra were measured on a Shimadzu
IR-460 spectrometer. 1H and 13C NMR spectra were measured (CDCl3
solution) with a Bruker DRX-500 Avance spectrometer at 250.0 and
62.5 MHz, respectively. Mass spectra were recorded on a Finnigan-Matt
8430 mass spectrometer operating at an ionization potential of 20 eV.
4.1 General procedure
A homogenous mixture of salicyl aldehyde derivative (1 mmol), dialkyl-
acetylenedicarboxylate (1 mmol), and powdered silica-gel (0.7 g) was heated in
a oven at 908C for 45 min and then placed over a column of silica-gel (12 g).
The column chromatography was washed using ethyl acetate–light petroleum
ether (1:10) as eluent. The solvent was removed under reduced pressure, and
the residue was dissolved in chloroform (2 ml) and then stirred at room tempera-
ture for 30 min. The solvent was removed under reduced pressure, and the
products were obtained as solidified oils. Relative population of E and Z stereoi-
somers for the compounds 3a–c and 7a,b were determined via their 1H
NMR spectra. The characterization data of the new compounds are given next.
4.1.1 Dimethyl 2-(2-Formylphenoxy)-2-butenedioate (3a)
White solidified oil, yield 54%, IR (KBr) (ymax, cm21): 3085 (CH, arom);
3008 (CH, alipha); 2951 and 2885 (CH, aldehyde); 1727 (C55O, carbonyl);
1288 (C-O, ether). Anal. calcd. for C13H12O6 (264): C, 59.09; H, 4.58;
found: C, 59.05; H, 4.53%. MS (m/z): 264 (Mþ); %Z ¼ 87 and %E ¼ 13.
1H NMR (CDCl3) for Z stereoisomer; dH: 3.70 and 3.76 (6H, 2 s, 2 OCH3);
6.74 (1H, s, 55CH); 6.81–7.92 (4H, m, arom.); 10.53 (1H, s, aldehyde). 13C
NMR (CDCl3) for Z stereoisomer: dC: 52.13 and 53.23 (2 OCH3); 115.33,
116.68, 123.71, 128.55, and 135.45 (5CH); 125.71, 149.06 and 158.86 (3
C); 162.08 and 163.40 (2 C55O of two esters); 188.94 (C55O of aldehyde).
1H NMR (CDCl3) for E stereoisomer, dH: 3.68 and 3.91 (6H, 2 s, 2 OCH3);
5.23 (1H, s, ¼CH); 6.81–7.94 (4H, m, arom.); 10.27 (1H, s, aldehyde).
4.1.2 Dimethyl 2-Hydroxyl-2H-chromene-2,3-dicarboxylate (5a)
White solidified oil, yield 41%, IR (KBr) (ymax, cm21): 3470 (OH, alcohol);
3015 (CH, arom); 2961 (CH, alipha); 1734 (C55O, carbonyl); 1233 (C-O,

3186
N. Noshiranzadeh and A. Ramazani
ether). Anal. calcd. for C13H12O6 (264): C, 59.09; H, 4.58; found: C, 59.16; H,
1
4.51%. MS(m/z): 264 (Mþ). H NMR (CDCl3) dH: 3.86 and 3.95 (6H, 2s, 2
OCH3); 5.11 (1H, s, exchanged by D2O addition, OH); 6.98–7.41 (4 H, m,
arom.); 7.81 (1H, s, 55CH). 13C NMR (CDCl3) dC: 52.15 and 54.06
(2 OCH3); 92.96 (C-OH); 116.84, 122.53, 129.16, 132.74, and 135.37 (5CH);
117.95, 121.07, and 151.25 (3 C); 164.42 and 169.69 (2 C55O of ester).
4.1.3 Dimethyl 2-(4-Bromo-2-formylphenoxy)-2-butenedioate (3b)
White solidified oil, yield 50%, IR (KBr) (nmax, cm21): 3077 (CH, arom);
2962 and 2861 (CH, aldehyde); 1727 (C55O, ester); 1689 (C55O,
aldehyde); 1288 (C-O, ether). Anal. calcd. for C13H11BrO6 (343): C, 45.50;
H, 3.23; found: C, 45.59; H, 3.16%. MS (m/z): 342 (Mþ); 344 (Mþ þ 2).
1
%Z ¼ 86 and %E ¼ 14. H NMR (CDCl3) for Z stereoisomer, dH: 3.74 and
3
3.79 (6H, 2s, 2 OCH3); 6.72 (1H, s, 55CH); 6.77 (1H, d, JHH ¼ 6.3 Hz,
3
4
arom.); 7.58 (1H, dd, JHH ¼ 6.3 Hz, JHH ¼ 2.5 Hz, arom.); 8.02 (1H, d,
4JHH ¼2.5 Hz, arom.); 10.46 (1H, s, aldehyde). 13C NMR (CDCl3) for Z
stereoisomer, dC: 52.32 and 53.43 (2 OCH3); 117.29, 117.35, 131.26 and
137.95 (4 CH); 116.79, 126.92, 148.95, and 157.77 (4 C); 161.81 and
1
163.22 (2 C55O of ester); 187.57 (C55O, aldehyde). H NMR (CDCl3) for
E stereoisomer, dH: 3.72 and 3.92 (6H, 2 s, 2 OCH3); 5.3 (1H, s, 55CH);
7.08-8.08 (3H, m, arom.); 10.2 (1H, s, aldehyde).
4.1.4 Dimethyl 6-Bromo-2-hydroxy-2H-chromene-
2,3-dicarboxylate (5b)
White powder, mp 74.5–76.18C, yield 45%, IR (KBr) (ymax, cm21): 3470
(OH, alcohol); 2961 (CH, arom.); 2860 (CH, alipha.); 1711 (C55O,
carbonyl); 1240 (C-O, ether). Anal. calcd. for C13H11BrO6 (343): C, 45.50;
H, 3.23; found: C, 45.44; H, 3.28%. MS (m/z): 342 (Mþ), 344 (Mþ þ 2).
1H NMR (CDCl3) dH: 3.83 and 3.90 (6H, 2s, 2 OCH3), 5.14 (1H, s,
exchanged by D2O addition, OH), 6.86–7.47 (3H, m, arom.); 7.71 (1H, s,
55CH). 13C NMR (CDCl3) dC: 52.31 and 54.14 (2 OCH3); 93.02 (C-
OH);118.66, 131.22, 133.91, and 135.15 (4 CH); 114.55, 119.74, 122.26,
and 150.24 (4 C); 164.03 and 169.30 (2 C55O of ester).
4.1.5 Diethyl 2-(4-Bromo-2-formylphenoxy)-2-butenedioate (3c)
White solidified oil, yield 55%, IR (KBr) (nmax, cm21): 3077 (CH, arom.);
2962 and 2861 (CH, aldehyde); 1727 (C55O, ester); 1689 (C55O,
aldehyde); 1288 (C-O, ether). Anal. calcd. for C15H15BrO6 (371): C, 48.54;
H, 4.07; found: C, 48.61; H, 4.11%. MS (m/z): 370 (Mþ), 372 (Mþ þ 2);
1
%Z ¼ 88 and %E ¼ 12. H NMR (CDCl3) for Z stereoisomer, dH: 1.32 and
3
1.9 (6H, 2 t, JHH ¼7.0 Hz, 2 CH3 of 2 Et); 4.25 and 4.33 (4H, 2 q,
3JHH ¼ 7.0 Hz, 2 OCH2 of 2 OEt); 5.53 (1H, s, 55CH); 6.89–8.05 (3 H, m,

Reaction between Ortho-Hydroxy Aromatic Aldehydes
3187
arom.); 10.23 (1H, s, aldehyde). 13C NMR (CDCl3) for Z stereoisomer, dC:
13.61 and 14.61 (2 CH3 of 2 Et); 61.05 and 62.12 (2 OCH2 of 2 OEt);
115.59, 119.78, 132.87, and 139.05 (4 CH); 115.25, 127.75, 141.57, and
158.10 (4 C); 166.33 and 167.65 (2 C55O of ester); 187.30 (C55O,
1
aldehyde). H NMR (CDCl3) for E stereoisomer, dH: 1.18 and 1.24 (6H, 2 t,
3
3JHH ¼ 7.0 Hz, 2 CH3 of 2 Et); 4.18 and 4.22 (4 H, 2 q, JHH ¼ 7.0 Hz of 2
3
OCH2 of 2 OEt); 6.74 (1H, 1 s, ¼CH); 6.77 (1H, d, JHH ¼ 6.0 Hz, arom.);
3
4
7.58 (1H, dd, JHH ¼ 6.0 Hz, JHH ¼ 2.5 Hz, arom); 8.00 (1H, d,
4JHH ¼ 2.5 Hz, arom.); 10.46 (1H, s, aldehyde). 13C NMR (CDCl3) for E
stereoisomer, dC: 13.89 and 13.99 (2 CH3 of 2 Et); 61.40 and 62.82 (2
OCH2 of 2 OEt); 117.42, 117.56, 131.13, and 137.94 (4 CH); 116.65,
126.90, 148.68, and 157.91 (4 C); 161.31 and 162.93 (2 C55O of ester);
187.56 (C55O, aldehyde).
4.1.6 Diethyl 6-Bromo-2-hydroxy-2 H-chromene-2,3-dicarboxylate (5c)
White solidified oil, yield 40%, IR (KBr) (ymax, cm21): 3470 (OH, alcohol);
2961 (CH, arom.); 2860 (CH, alipha); 1711 (C55O, carbonyl); 1240 (C-O,
ether). Anal. calcd. for C15H15BrO6 (371): C, 48.54; H, 4.07; found: C,
1
48.62; H, 4.00%. MS (m/z): 370 (Mþ), 372 (Mþ þ 2). H NMR (CDCl3)
3
dH: 1.28 and 1.36 (6H, 2 t, JHH ¼ 7.3 Hz, 2 CH3 of 2 Et); 4.28 and 4.37
3
(4 H, 2 q, JHH ¼7.3 Hz, 2 OCH2 of 2 Et); 5.67 (1H, s, exchanged by
D2O addition, OH); 6.98–7.89 (3H, m, arom.); 7.69 (1H, s, 55CH). 13C
NMR (CDCl3) dC: 13.84 and 14.08 (2 CH3 of 2 Et); 61.35 and 63.56 (2
OCH2 of 2 Et); 93.10 (C-OH); 118.63, 131.14, 133.66, and 134.94 (4CH);
114.39, 119.88, 122.66, and 150.28 (4 C); 163.55 and 168.80 (2 C55O of
two esters).
4.1.7 Dimethyl 2-[(1-Formyl-2-naphthyl)oxy]-2-butenedioate (7a)
Yellow solidified oil, yield 50%, IR (KBr) (ymax, cm21): 2953 and 2876 (CH,
aldehyde), 1738 (C55O, carbonyl); 1684 (C55C, alkene); 1269 and 1169 (C-
O, ether). Anal. calcd. for C17H14O6 (314): C, 64.97; H, 4.49; found: C,
1
65.06; H, 4.43%. MS (m/z): 314 (Mþ), %Z ¼ 80 and %E ¼ 20. H NMR
(CDCl3) for Z stereoisomer, dH: 3.71 and 3.77 (6H, 2 s, 2 OCH3); 6.82 (1H,
3
3
s, ¼CH); 7.05 (1 H, d, JHH ¼ 9.0 Hz, arom.); 8.00 (1 H, d, JHH ¼ 9.0 Hz,
3
3
arom.); 7.80 (1 H, d, JHH ¼ 8.0 Hz, arom.); 7.49 (1H, t, JHH ¼ 7.3 Hz,
3JHH ¼ 8.0 Hz, arom.); 7.67 (1H, t, JHH ¼ 7.3 Hz, JHH ¼ 8.8 Hz, arom.);
3
3
9.31 (1H, d, JHH ¼ 8.8 Hz, arom.); 10.98 (1H, s, H aldehyde). 13C NMR
3
(CDCl3) for Z stereoisomer, dC: 52.22 and 53.34 (2 OCH3); 114.73, 116.97,
125.48, 125.77, 128.27, 130.04, and 137.01 (7CH); 117.92, 130.19, 131.32,
148.10, and 160.93 (5C); 162.11 and 163.41 (2 C55O of two esters); 191.41
(C55O of aldehyde). 1H NMR (CDCl3) for E stereoisomer, dH: 3.70 and 3.95
3
(6 H, 2 s, 2 OCH3); 5.26 (1H, s, 55CH); 7.30 (1H, d, JHH ¼ 9.0 Hz, arom);

3188
N. Noshiranzadeh and A. Ramazani
8.14 (1H, d, 3JHH ¼ 9.0 Hz, arom.); 7.46–9.29 (4H, m, arom.); 10.70 (1H, s,
aldehyde).
4.1.8 Dimethyl 3-Hydroxy-3 H-benzo[ f ]chromene-
2,3-dicarboxylate (9a)
Yellow solidified oil, yield 46%. IR (KBr) (ymax, cm21): 3446 (OH, alcohol);
2930 (CH, alipha), 1746 (C55O, carbonyl); 1707 (C55C, alkene); 1284 (C-O,
ether). Anal. calcd. for C17H14O6 (314): C, 64.97; H, 4.49; found: C, 65.07; H,
4.55%. MS (m/z): 314 (Mþ). 1H NMR (CDCl3) dH: 3.87 and 3.93 (6H, 2 s, 2
OCH3); 5.23 (1H, s, exchanged by D2O addition, OH); 7.18 (1H, d,
3
3JHH ¼ 8.8 Hz, arom.); 7.86 (1H, d, JHH ¼ 8.8 Hz, arom.); 7.8 (1H, d,
3
3
3JHH ¼ 8.0 Hz, arom.); 7.44 (1H, t, JHH ¼ 8.0 Hz, JHH ¼ 7.3 Hz, arom);
3
3
7.60 (1H, t, JHH ¼ 7.3 Hz, JHH ¼ 8.3 Hz, arom.); 8.15 (1H, d,
3JHH ¼ 8.3 Hz, arom.); 8.59 (1H, s, 55CH). 13C NMR (CDCl3) dC: 52.20
and 54.14 (2 OCH3); 93.08 (C-OH); 117.63, 121.10, 124.78, 127.89,
128.80, 131.06, and 133.53 (7 CH); 110.99, 119.18, 129.61, 131.06, and
150.52 (5 C); 164.68 and 169.80 (2 C55O of two esters).
4.1.9 Diethyl 2-[(1-Formyl-2-naphthyl)oxy]-2-butenedioate (7b)
Yellow solidified oil, yield 55%, IR (KBr) (ymax, cm21): 2953 and 2876 (CH,
aldehyde), 1738 (C55O, carbonyl); 1684 (C55C, alkene); 1269 and 1169 (C-O,
ether). Anal. calcd. for C19H18O6 (342): C, 66.66; H, 5.30; found: C, 66.50; H,
5.26%. MS (m/z): 342 (Mþ), %Z ¼ 83 and %E ¼ 17. 1H NMR (CDCl3) for Z
stereoisomer, dH: 1.16 and 1.18 (6H, 2 t, 3JHH ¼ 7.0 Hz, 2 CH3 of 2 Et); 4.15
and 4.18 (4 H, 2 q, 3JHH ¼ 7.0 Hz, 2 CH2 of 2 OEt); 6.81 (1H, 1 s,55CH); 7.05
(1H, d, 3JHH ¼ 9.0 Hz, arom.); 8.00 (1H, d, 3JHH ¼ 9.0 Hz, arom.); 7.80 (1H,
d, 3JHH ¼ 8.0 Hz, arom.); 7.49 (1H, t, 3JHH ¼ 7.3 Hz, 3JHH ¼ 8.0 Hz, arom.);
3
3
7.67 (1H, t, JHH ¼ 7.3 Hz, JHH ¼ 8.8 Hz, arom.); 9.31 (1H, d,
3JHH ¼ 8.8 Hz, arom.); 10.98 (1H, s, aldehyde). 13C NMR (CDCl3) for Z
stereoisomer, dC: 13.85 and 13.97 (2 CH3 of 2 Et); 61.28 and 62.70 (2
OCH2 of 2 OEt); 114.88, 117.21, 125.45, 125.71, 128.27, 130.00, and
136.97 (7CH); 117.87, 130.12, 131.28, 148.88, and 160.82 (5C); 161.61 and
163.07 (2 C55O of two esters); 191.49 (C55O of aldehyde). 1H NMR
3
(CDCl3) for E stereoisomer, dH: 1.25 and 1.40 (6 H, 2 t, JHH ¼ 7.0 Hz, 2
3
CH3 of 2 Et); 4.17 and 4.40 (4 H, 2 q, JHH ¼ 7.0 Hz, 2 CH2 of 2 OEt);
3
5.26 (1H, s,55CH); 7.30(1H, d, JHH ¼ 9.0 Hz, arom.); 8.14 (1H, d,
3
3JHH ¼ 9.0 Hz, arom); 7.89 (1H, d, JHH ¼ 8.0 Hz, arom.); 7.6 (1H, t,
3
3
3JHH ¼ 7.3 Hz, JHH ¼ 8.0 Hz, arom.); 7.70 (1H, t, JHH ¼ 7.3 Hz,
3JHH ¼ 8.8 Hz, arom.); 9.25 (1H, d, JHH ¼ 8.8 Hz, arom.); 10.70 (1H, s,
3
aldehyde). 13C NMR (CDCl3) for E stereoisomer, dC: 58.70 and 60.96
(2 CH2 of 2OEt); 119.60, 127.00, 128.43, 137.52, and 159.67 (5 C); 193.25
(C55O of aldehyde).

Reaction between Ortho-Hydroxy Aromatic Aldehydes
3189
4.1.10 Diethyl 3-Hydroxy-3H-benzo[ f ]chromene-
2,3-dicarboxylate (9b)
Yellowsolidified oil, yield 40%, IR(KBr) (ymax,cm21):3430(OH,alcohol);2984
(CH, alipha), 1753 (C55O, carbonyl); 1692 (C55C, alkene); 1269 (C-O, ether).
Anal. calcd. for C19H18O6 (342): C, 66.66; H, 5.30; found: C, 66.72; H, 5.23%.
MS (m/z): 342(Mþ). 1H NMR (CDCl3) dH: 1.33 and 1.37 (6H, 2 t,
3JHH ¼ 7.3 Hz, 2 CH3 of 2 Et); 4.34 and 4.37 (4H, 2 q, 3JHH ¼ 7.3 Hz, 2 CH2
of 2 OEt); 5.36 (1H, s, exchanged by D2O addition, OH); 7.18 (1H, d,
3
3JHH ¼ 8.8 Hz, arom.); 7.86 (1H, d, JHH ¼ 8.8 Hz, arom.): 7.8 (1H, d,
3
3
3JHH ¼ 8.0 Hz, arom.); 7.44 (1H, t, JHH ¼ 8.0 Hz, JHH ¼ 7.3 Hz, arom.);
7.60 (1H, t, 3JHH ¼ 7.3 Hz, 3JHH ¼ 8.3 Hz, arom.); 8.15 (1H, d, 3JHH ¼ 8.3 Hz,
arom.); 8.59 (1H, s, 55CH). 13C NMR (CDCl3) dC: 13.88 and 14.23 (2 CH3 of 2
Et); 61.18 and 63.56 (2 OCH2 of 2 OEt); 93.20 (C-OH); 117.70, 121.12,
124.70, 127.81, 128.77, 131.78, and 133.31 (7 CH); 111.10, 119.63, 129.6,
131.78, and 150.54 (5 C); 164.21 and 169.37 (2 C55O of two esters).
ACKNOWLEDGMENTS
This work was supported by Sandoogh Hemayate as Pajuoheshgharane
Keshvare Iran.
REFERENCES
1. Deka, N.; Mariotte, A.-M.; Boumendjel, A. Green Chem. 2001, 3, 263–264.
2. Kidwai, M.; Venkataramanan, R.; Dave, B. Green Chem. 2001, 3, 278–279.
3. Shaabani, A.; Soleimani, E.; Khavasi, H. R.; Hoffmann, R.-D.; Rodewald, U. C.;
Pottgen, R. Tetrahedron Lett. 2006, 47, 5493–5496.
4. Alizadeh, A.; Rostamnia, S.; Zhu, L.-G. Tetrahedron 2006, 62, 5641–5644.
5. Shaabani, A.; Soleimani, E.; Maleki, A. Tetrahedron Lett. 2006, 47, 3031–3034.
6. Shaabani, A.; Teimouri, M. B.; Bijanzadeh, H. R. Tetrahedron Lett. 2002, 43,
9151–9154.
7. Shaabani, A.; Yavari, I.; Teimouri, M. B.; Bazgir, A.; Bijanzadeh, H. R. Tetra-
hedron 2001, 57, 1375–1378.
8. Ramazani, A.; Bodaghi, A. Tetrahedron Lett. 2000, 41, 567–568.
9. Ramazani, A.; Ahmadi, E. Phosphorus, Sulfur Silicon Relat. Elem. 2003, 178,
2659–2661.
´
10. Zhu, J., Bienayme, H., Eds.; Multicomponent Reactions; Wiley-VCH: Weinheim,
2005.
11. Ramazani, A.; Souldozi, A. Phosphorus, Sulfur Silicon Relat. Elem. 2003, 178,
2663–2666.
12. Ramazani, A.; Souldozi, A. Phosphorus, Sulfur Silicon Relat. Elem. 2004, 179,
529–533.
13. Ramazani, A.; Abbasi-Motejadded, A.; Ahmadi, E. Phosphorus, Sulfur Silicon
Relat. Elem. 2006, 181, 233–236.
14. Ghosh, S. K.; Hsung, R. P.; Liu, J. J. Am. Chem. Soc. 2005, 127, 8260–8261.