Unexpected Pd-catalyzed coupling, propargyl-allenyl isomerization and Alder-ene reaction: Facile synthesis of some not readily available 2,3-dihydrofuran derivatives

Article abstract of DOI:10.1021/jo900440u

(Chemical Equation Presented) An interesting sequential reaction involving Pd-catalyzed coupling, propargyl-allenyl isomerization, and Alder-ene cycloaddition is reported, providing a facile synthesis of some not readily available 2,3-dihydrofurans from e

Full text of DOI:10.1021/jo900440u

Unexpected Pd-Catalyzed Coupling, Propargyl-Allenyl
Isomerization and Alder-Ene Reaction: Facile Synthesis of Some
Not Readily Available 2,3-Dihydrofuran Derivatives
Ruwei Shen,† Shugao Zhu,† and Xian Huang*,†,‡
Department of Chemistry, Zhejiang UniVersity, Xixi Campus, Hangzhou 310028, P. R. China, and State
Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy
of Sciences, Shanghai 200032, P. R. China
huangx@mail.hz.zj.cn
ReceiVed February 27, 2009
An interesting sequential reaction involving Pd-catalyzed coupling, propargyl-allenyl isomerization, and
Alder-ene cycloaddition is reported, providing a facile synthesis of some not readily available 2,3-
dihydrofurans from electron-deficient vinyl or aromatic halides and 1-aryl-prop-2-ynyl 3′-methylbut-2′-
enyl ethers.
Introduction
cent spirocycles, and some other pharmaceutically interesting
heterocycles.4 Previously, we also developed a useful palladium-
catalyzed sequential reaction utilizing an intramolecular [4 +
2] cyclization involving an allene intermediate as a key step,
providing a facile and stereoselective synthesis of structurally
complex polycyclic scaffolds,5a and very recently an efficient
method to produce a variety of structurally diverse dihy-
droisobenzofuran derivatives based on this line was reported
The synthesis of various cyclic compounds by efficient
formation of carbon-carbon bonds is a highly desired activity
in organic synthesis.1 Sequential reaction represents one of the
most powerful tools for the rapid construction of complex
molecular skeletons via a process that often features multibonds
and stereocenters formed in a single stroke with high efficiency.2,3
Mu¨ller et al. have pioneered Sonogashira coupling-isomerization
sequential reactions for the synthesis of a variety of useful
compounds including chalcones, pyrazolines, pyrroles, fluores-
(3) For recent examples, see: (a) Campo, M. A.; Huang, Q.; Yao, T.; Tian,
Q.; Larock, R. C. J. Am. Chem. Soc. 2003, 125, 11506. (b) von Zezschwitz, P.;
Petry, F.; de Meijere, A. Chem.sEur. J. 2001, 7, 4035. (c) Karpov, A. S.; Merkul,
E.; Oeser, T.; Muller, T. J. J. Chem. Commun. 2005, 2581. (d) Larock, R. C.;
Tian, Q. J. Org. Chem. 2001, 66, 7372. (e) Salem, B.; Klotz, P.; Suffert, J. Org.
Lett. 2003, 5, 845. (f) Catellani, M.; Motti, E.; Baratta, S. Org. Lett. 2001, 3,
3611. (g) Blond, G.; Bour, C.; Salem, B.; Suffert, J. Org. Lett. 2008, 10, 1075.
(h) Couty, S.; Liegault, B.; Meyer, C.; Cossy, J. Org. Lett. 2004, 6, 2511.
(4) (a) Braun, R. U.; Ansorge, M.; Mu¨ller, T. J. J. Chem.sEur. J. 2006, 12,
9081. (b) D’Souza, D. M.; Rominger, F.; Mu¨ller, T. J. J. Angew. Chem., Int.
Ed. 2005, 44, 153. (c) D’Souza, D. M.; Kiel, A.; Herten, D.-P.; Mu¨ller, T. J. J.
Chem.sEur. J. 2008, 14, 529. (d) D’Souza, D. M.; Rominger, F.; Mu¨ller, T. J. J.
Chem. Commun. 2006, 4096. (e) D’Souza, D. M.; Liao, W.-W.; Mu¨ller, T. J. J.
Org. Biomol. Chem. 2008, 6, 532. (f) Schramm, O. G.; Dediu, ne´e.; Mu¨ller,
T. J. J. AdV. Synth. Catal. 2006, 348, 2565. (g) Braun, B. U.; Zeitler, K.; Mu¨ller,
T. J. J. Org. Lett. 2001, 3, 3297. (h) Braun, B. U.; Zeitler, K.; Mu¨ller, T. J. J.
Org. Lett. 2000, 2, 4181. (ah) Schramm, O. G.; Dediu, ne´e.; Oeser, T.; Mu¨ller,
T. J. J. J. Org. Chem. 2006, 71, 3494.
† Zhejiang University.
‡ Shanghai Institute of Organic Chemistry.
(1) (a) Trost, B. M.; van Vranken, D. L. Chem. ReV. 1998, 96, 395. (b)
Negishi, E.; Coperet, C.; Ma, S.; Liou, S.; Liu, F. Chem. ReV. 1996, 96, 365. (c)
Negishi, E. Pure Appl. Chem. 1992, 74, 323. (d) de Meijere, A.; von Zezschwitz,
P.; Bra¨se, S. Acc. Chem. Res. 2005, 38, 413.
(2) For reviews, see: (a) Ho, T. L. Tandem Organic Reactions; John Wiley
& Sons: New York, NY, 1992. (b) Tietze, L. F.; Brasche, G.; Gericke, K. M.
Domino Reaction in Organic Synthesis; Wiley-VCN: Weinheim, Germany, 2006.
(c) Padwa, A.; Weingarten, M. D. Chem. ReV. 1996, 96, 223. (d) Tietze, L. F.
Chem. ReV. 1996, 96, 115. (e) Arns, S.; Barriault, L. Chem. Commun. 2007,
2211. (f) Tietze, L. F.; Modi, A. Med. Res. ReV. 2000, 20, 304. (g) Nicolaou,
K. C.; Edmonds, D. J.; Bulger, P. G. Angew. Chem., Int. Ed. 2006, 45, 7134.
(h) Posner, G. H. Chem. ReV. 1986, 86, 831. (i) Parsons, P. J.; Penkett, C. S.;
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4118 J. Org. Chem. 2009, 74, 4118–4123
10.1021/jo900440u CCC: $40.75 2009 American Chemical Society
Published on Web 05/04/2009

Facile Synthesis of 2,3-Dihydrofuran DeriVatiVes
SCHEME 1
TABLE 2. Pd-Catalyzed Coupling, Propargyl-Allenyl
SCHEME 2
Isomerization, and Alder-Ene Reaction To Yield 2,3-Dihydrofurans
3a
entry
1 (R1, R2)
1a (CH3, H)
1a
1a
1a
1a
2 (Ar)
2a (Ph)
2b (p-CH3C6H4)
2c (p-ClC6H4)
2d (m-BrC6H4)
3, yieldb (%)
TABLE 1. Solvent and Base Effects on the Pd-Catalyzed
Coupling, Propargyl-Allenyl Isomerization, and Alder-Ene
Reaction
1
3a, 79
3b, 75
3c, 77
3d, 80
3e, 83
3f, 79
3g, 78
3h, 80
3i, 83
3j, 65c
3k,63c
2
3c
4
5
6
7
8
9
10
11
2e (p-FC6H4)
1b (allyl, H)
2a
2b
2c
2e
1b
1b
1b
1c (3-methylbut-2-enyl, CH3) 2b
1c 2e
entry
solvent
basea
Et3N
yield of 3ab
1
2
3
4
5
6
toluene
THF
79
76
75
c
a Unless otherwise noted, the reaction was carried out using 1 (0.25
mmol) and 2 (0.3 mmol) in the presence of 5 mol % PdCl2(PPh3)2 and 3
mol % of CuI in 1.8 mL of toluene and 0.6 mL of Et3N at room
temperature. b Isolated yields. c Unidentified byproducts observed.
Et3N
MeCN
toluene
toluene
toluene
Et3N
Et2NH
pyrrolidine
i-Pr2NH
c
c
enyl ether 2a in the presence of a catalytic amount of
Pd(PPh3)2Cl2 and CuI at room temperature for 18 h in toluene,8
we found that the reaction gave an inseparable mixture of the
ene-type product 3a together with the Sonogashira coupling
product 3a′, and no Diels-Alder product was formed (Scheme
2). Prolonging the reaction time to 66 h ultimately led to the
full conversion of 3a′ into the final product 3a, which was
determined by 1HNMR analysis of the crude product (Table 1,
entry 1). The reaction could be carried out in solvents such as
THF and MeCN with good yields (Table 1, entries 2 and 3).
However, the reaction was very sensitive to the amine bases
a Reactions were carried out using 1a (0.25 mmol), 2a (0.3 mmol), 5
mol % [PdCl2(PPh3)2], and 3 mol % of CuI in 1.8 mL of solvent and
0.6 mL of amine at room temperature. b Isolated yields. c No identified
product was obtained.
as well.5b During the course of our systematic investigation on
the scope of these reactions, it was surprising but also interesting
to observe that the reaction of 3-iodocyclohex-2-enone and
1-phenylprop-2-ynyl 3′-methylbut-2′-enyl ether led to a mixture
of Diels-Alder-type product I in 65% yield together with II in
10% yield (Scheme 1).5a The formation of 2,3-dihydrofuran II
was presumed to be a result of the competitive Alder-ene
reaction of the in situ generated allene intermediate. This
reaction would be an alternative way to access some structurally
interesting 2,3-dihydrofurans and may be useful as dihydrofuran
(6) (a) Dean, F. M.; Sargent, M. V. In ComprehensiVe Heterocyclic
Chemistry; Bird, C. W., Cheeseman, G. W. H., Eds.; Pergamon: New York,
1984; Vol. 4, Part 3, pp 531-598. (b) Lipshutz, B. H. Chem. ReV. 1986, 86,
795. For examples of natural products with 2,3-dihydrofuran unit, see: (c) Barton,
D. H. R.; Chung, H. T.; Gross, A. D.; Jackman, L. M.; Martin-Smith, M. J. Chem.
Soc. 1961, 5069. (d) von Dreele, R. B.; Pettit, G. R.; Ode, R. H.; Perdue, R. E.,
Jr.; White, J. D.; Manchand, P. S. J. Am. Chem. Soc. 1975, 97, 3002. (e) Steyn,
P. S.; Vleggaar, R. J. Chem. Soc., Perkin Trans. 1 1974, 2250. (f) Fraga, B. M.
Nat. Prod. Rep. 1992, 9, 217. (g) Sekizawa, R.; Ikeno, S.; Nakamura, H.;
Naganawa, H.; Matsui, S.; Iinuma, H.; Takeuchi, T. J. Nat. Prod. 2002, 65,
1491. (h) Merrit, A. T.; Ley, S. V. Nat. Prod. Rep. 1992, 9, 243.
is a very important unit in many potentially useful natural
6,7
products.
As a matter of fact, further investigation demon-
strated that this pathway could preferentially occur by delicately
tuning the substrates. In this paper, we wish to report our results
on this cascade Pd-catalyzed coupling, propargyl-allenyl
isomerization, and Alder-ene reaction, leading to some not
readily available 2,3-dihydrofuran derivatives.
(7) For recent examples of the synthesis of 2,3-dihydrofuran derivatives, see:
(a) Kilroy, T. G.; O’ Sullivan, T. P.; Guiry, P. J. Eur. J. Org. Chem. 2005,
4929. (b) Chuang, C.-P.; Chen, K.-P.; Hsu, Y.-L.; Tsai, A.-I.; Liu, S.-T.
Tetrahedron 2008, 64, 7511. (c) Gais, H.-J.; Reddy, L. R.; Babu, G. S.; Raabe,
G. J. Am. Chem. Soc. 2004, 126, 4859. (d) Bernard, A. M.; Frongia, A.; Piras,
P. P.; Secci, F.; Spiga, M. Org. Lett. 2005, 7, 4565. (e) Bernard, A. M.; Frongia,
A.; Piras, P. P.; Secci, F.; Spiga, M. Org. Lett. 2005, 7, 4565. (f) Xing, C.; Zhu,
S. J. Org. Chem. 2004, 69, 6486.
Results and Discussion
When our efforts turned to the reaction of 3-iodo-2-methyl-
cyclohex-2-enone 1a and 1-phenylprop-2-ynyl 3′-methylbut-2′-
(8) Thorand, S.; Krause, N. J. Org. Chem. 1998, 63, 8551.
J. Org. Chem. Vol. 74, No. 11, 2009 4119

Shen et al.
TABLE 3. Pd-Catalyzed Coupling, Propargyl-Allenyl Isomerization, and Alder-Ene Reaction To Yield 2,3-Dihydrofurans 4a
a Unless otherwise noted, the reaction was carried out using 1 (0.25 mmol) and 2 (0.3 mmol) in the presence of 5 mol % PdCl2(PPh3)2 and 3 mol % of CuI
in 1.8 mL of toluene and 0.6 mL of Et3N at room temperature. b Isolated yields. c Small amount of Diels-Alder product was observed. d Obtained as
diastereoisomers. e Ratio of Z/E isomers was deduced from 1H NMR analysis; see Supporting Information. f Reaction was carried out at 100 °C.
employed. Diethylamine, pyrrolidine, and diisopropylamine,
which are frequently employed in Sonogashira coupling reac-
tions, were found to be incompatible in this reaction (Table 1,
entries 4-6).
isolated (eq 1). When an allyl group was introduced to the
2-position of the 3-iodocyclohex-2-enone, i.e., 1b, 1c, the
reaction proceeded smoothly to afford the expected products
(Table 2, entries 6-11).
Under the established conditions, we examined the scope
of the reaction. As indicated in Table 2, a variety of propargyl
allyl ethers 2 could be applied to produce the corresponding
products in good yields. Ar could be a meta- or para-
substituted phenyl group either with an electron-donating or
electron-withdrawing group incorporated. The presence of a
substituent on the ortho position of the benzene ring of the
propargyl allyl ether affected the reaction negatively. For
example, when Ar ) o-BrC6H4, the reaction failed to afford
the expected product and only the coupled product 3l was
With these encouraging results, we further investigated the
reaction scope by employing a variety of other electron-
4120 J. Org. Chem. Vol. 74, No. 11, 2009

Facile Synthesis of 2,3-Dihydrofuran DeriVatiVes
TABLE 4. Pd-Catalyzed Coupling, Propargyl-Allenyl Isomerization, and Alder-Ene Reaction To Yield 2,3-Dihydrofurans 6a
a Unless otherwise noted, the reaction was carried out using 5 (0.25 mmol) and 2 (0.3 mmol) in the presence of 5 mol % PdCl2(PPh3)2 and 3 mol %
of CuI in 1.8 mL of THF and 0.6 mL of Et3N at 40 °C. b Isolated yields. c Reaction was carried out in toluene at 80 °C.
deficient vinyl iodides (Table 3). The reaction proceeded
smoothly at room temperature to afford the corresponding
2,3-dihydrofuran 4a in good yields when 2-allyl-3-iodocy-
clopent-2-enone 1d was employed (Table 3, entry 1). Similar
results were observed for 2-substituted 3-iodobutenolides 1f,
1g, 1h, and 1i (Table 3, entries 4-8). When (Z)-ethyl
3-iodoacrylate 1j was employed to react with 1-aryl-prop-
2-ynyl 3′-methylbut-2′-enyl ethers 2e and 2g, respectively,
however, we obtained the products 4i and 4j both as a mixture
of the Z/E isomers (Table 3, entries 9 and 10). The
isomerization of the double bonds may be explained by
the possibility that the resulted Z-4i and Z-4j are quite
instable and easily transform to their E-isomers as a result
of the intramolecular steric repulsive effect between the ester
group and the dihydrofuran moiety. In addition, it is also
interesting to find that the reaction preferentially produced
the Alder-ene products 4b and 4c9 in 63% and 65% yields,
respectively, when 3-iodocyclopent-2-enone was employed
(Table 3, entries 2 and 3).10
Furthermore, this sequential reaction also could be extended
to electron-deficient aromatic or heteroaromatic halides including
1-iodo-4-nitrobenzene 5a, 4-iodobenzonitrile 5b, and 2-bro-
mopyridine 5c, producing the corresponding 2,3-dihydrofuran
derivatives in moderate to good yields (Table 4, entries 1-7).
When only a single methyl or long-chain alkyl group such
as n-pentyl was introduced at the 3-position of the alkene moiety
of the propargyl allyl ether, i.e., 2h or 2i, the corresponding
product 4k or 4l was also formed, implying that the subsequent
J. Org. Chem. Vol. 74, No. 11, 2009 4121

Shen et al.
SCHEME 3
the stereochemistry of 4l and 4m was further established by
the NOESY analysis.
As depicted in Scheme 4, this reaction can be rationalized
by a consecutive process involving a Pd-catalyzed coupling
reaction between the electron-deficient vinyl or aromatic iodide
and the propargyl allyl ether to produce the enyne intermediate
A, base-promoted propargyl-allenyl isomerization to give the
ene-allene intermediate B,11 and the final Alder-ene cyclization
to afford the 2,3-dihydrofuran derivatives via two possible
transition states B-TS1 (typically for the formation of 4k and
4l) and B-TS2 (typically for 4m). Accordingly, the following
should be noted: (1) The formation of the allene intermediate
is crucial for the subsequent Alder-ene reaction since controlled
experiments show that the treatment of the enyne 7 in the
presence of excessive triethyl amine at 40 °C for 4 d ultimately
gave 6a in 63% yield, but direct heating of 7 even under reflux
for 24 h in toluene did not result in any product 6a (Scheme
5). (2) The reason that the ene-allene intermediate B favors an
Alder-ene reaction to conclude the sequence rather than an
intramolecular Diels-Alder reaction may be attributed to the
steric repulsive interaction in the transition state B-TS3 for the
[4 + 2] cycloaddition, which makes this pathway disfavored
(Scheme 4). (3) The Alder-ene reactions of ene-allenes and
yne-allenes remain understudied, and only limited examples
either employing high temperature12 or with the assistance of
transition metal complexes13 have been reported. Therefore, our
observation on this mild reaction may be of considerable interest.
SCHEME 4. Proposed Mechanism for the Reaction
Conclusion
In conclusion, we have disclosed an interesting sequential
reaction in which the in situ generated ene-allene intermediates
could proceed via an Alder-ene reaction under very mild
conditions to produce some not readily available 2,3-dihydro-
furan derivatives. As demonstrated, a variety of electron-
deficient vinyl or aromatic halides and 1-aryl-prop-2-ynyl allyl
ethers can be employed in this reaction. We proposed a plausible
mechanism involving two possible transition states for the final
Alder-ene cyclization to rationalize the obtained results. It
should be noted that the in situ generated ene-allene intermediate
favors an Alder-ene reaction to conclude the sequence rather
than the Diels-Alder reaction probably as a result of the steric
hindrance of the transition state for the [4 + 2] cycloaddition.
Further efforts in this area are currently underway.
(9) X-ray crystal data for compound 4c: C19H19ClO2; MW ) 314.79;
orthorhombic, space group Fdd2; a ) 31.869(5), b ) 36.630(6), c ) 5.7018(10)
Å; R ) 90.00°, ꢀ ) 90.00°, µ ) 90.00°, V ) 6656(2) Å3, T ) 293 (2) K, Z )
16, Fcalcd ) 1.257 Mg/m3, µ ) 0.234 mm-1, µ ) 0.71073 Å; F(000) 2656,
independent reflections (Rint ) 0.1093), 9507 reflections collected; refinement
method, full-matrix least-squares refinement on F2; goodness-of-fit on F2 ) 0.822;
final R indices [I > 2σ(I)] R1 ) 0.0523, wR2 ) 0.1136.
SCHEME 5
(10) For the reaction of 3-iodocyclohex-2-enone and 2a, see Scheme 1.
(11) For review on O-substituted allenes, see: Krause, N.; Hashmi, A. S. K.
Modern Allene Chemistry; Wiley-VCH: Weinheim, Germany, 2004; Vol. 1,
Chapters 1 and 8.
(12) (a) Na¨rhi, K.; Franze´n, J.; Ba¨ckvall, J.-E. J. Org. Chem. 2006, 71, 2914.
(b) Hashmi, A. S. K.; Szeimies, G. Chem. Ber. 1994, 127, 1075. (c) Chia, H.-
A.; Kirk, B. E.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1974, 1209. (d)
Kirk, B. E.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1974, 1844. (e) Lee,
C. B.; Taylor, D. R. J. Chem. Soc., Perkin Trans. 1 1977, 1463. (f) Taylor,
D. R.; Wright, D. B. J. Chem. Soc., Perkin Trans. 1 1973, 956.
(13) (a) Brummond, K. M.; Chen, H.; Sill, P.; You, L. J. Am. Chem. Soc.
2002, 124, 15186. (b) Brummond, K. M.; Mitasev, B. Org. Lett. 2004, 6, 2245.
(c) Brummond, K. M.; Painter, T. O.; Probst, D. A.; Mitasev, B. Org. Lett. 2007,
9, 347. (d) Jiang, X.; Ma, S. J. Am. Chem. Soc. 2007, 129, 11600. (e) LIerena,
D.; Aubert, C.; Malacria, M. Tetrahedron Lett. 1996, 37, 7027. (f) Yamazaki,
T.; Hirokazu, U.; Sato, F. Tetrahedron Lett. 1998, 39, 7333.
Alder-ene reaction is still favored even with only one alkyl
group bearing hydrogens to be shifted (Scheme 3, eqs 1 and
2). Further experiments demonstrate that the reaction proceeded
smoothly as well to furnish the desired 2,3-dihydrofuran 4m
for 2-allyl-3-iodocyclopent-2-enone 1d and ether 2j in which
the n-butyl group was introduced at the 3-position of the alkene
moiety in a cis-fashion (Scheme 3, eq 3). The structures of these
compounds were determined by spectroscopic analysis, and
4122 J. Org. Chem. Vol. 74, No. 11, 2009

Facile Synthesis of 2,3-Dihydrofuran DeriVatiVes
J ) 15.6 Hz, 1H), 2.40-2.31 (m, 3H), 2.21-2.16 (m, 1H),
1.90-1.85 (m, 2H), 1.75 (s, 3H), 1.74 (s, 3H). 13C NMR (100M,
CDCl3): δ 199.7, 156.7, 152.4, 144.9, 131.9, 131.2, 128.6, 128.3,
127.5, 112.9, 107.9, 72.6, 54.4, 37.8, 30.7, 30.0, 22.4, 18.5, 11.0.
IR (neat): 2937, 1661, 1445, 1377, 1354, 1068. EIMS m/z (%):
308 (M+, 35), 186 (70), 105 (100). HRMS: calcd for C21H24O2,
308.1776; found, 308.1773.
Experimental Section
Typical Procedure for the Synthesis of 2,3-Dihydrofurans.
An oven-dried Schlenk tube containing a Teflon-coated stir bar was
charged with PdCl2(PPh3)2 (8.5 mg, 5 mol %), CuI (1.5 mg, 3 mol
%), and 3-iodocyclohex-2-enone 1a (59 mg, 0.25 mmol). The
Schlenk tube was sealed and then evacuated and backfilled with
N2 (3 cycles). A solution of propargyl allyl ether 2a (60 mg, 0.3
mmol) in 1.8 mL of toluene and 0.6 mL of Et3N was subsequently
injected to the Schlenk tube. The reaction mixture was stirred at rt
for 66 h. After the reaction was completed (monitored by TLC),
the mixture was quenched with diluted HCl and extracted with Et2O
(3 × 15 mL). The combined organic layers were dried over
anhydrous Na2SO4. After filtration and removal of the solvent in
vacuo, the residues were purified with flash chromatography (silica,
petroleum ether/ethyl acetate 8:1 v/v) to afford 3a (61 mg, 79%).
1H NMR (400M, CDCl3): δ 7.50 (d, J ) 8.0 Hz, 2H), 7.40-7.36
(m, 3H), 4.85 (s, 1H), 4.78 (s, 1H), 4.47-4.42 (m, 1H), 4.24-4.20
(m, 1H), 3.49-3.45 (m, 1H), 3.29 (d, J ) 15.6 Hz, 1H), 3.13 (d,
Acknowledgment. We are grateful to the National Natural
Science Foundation of China (Project Nos. 20732005 and
20872127) and National Basic Research Program of China (973
Program, 2009CB825300) for financial support.
Supporting Information Available: General experimental
procedures; spectroscopic data for 3a-3l, 4a-4m, 6a-6h, and
7; crystallographic characterization data of 4c. This material is
available free of charge via the Internet at http://pubs.acs.org.
JO900440U
J. Org. Chem. Vol. 74, No. 11, 2009 4123