Photo-irradiation of α-halo carbonyl compounds: A novel synthesis of α-hydroxy- and α,α′-dihydroxyketones

Article abstract of DOI:10.1016/j.tet.2005.01.010

The reaction of α-halo ketones (α-iodocycloalkanones, α-bromocycloalkanones, α-iodo-β-alkoxy esters, and α-iodoacyclicketones) with irradiation under a high-pressure mercury lamp gave the corresponding α-hydroxyketones in good yields. For α-bromoketones, it was found that α-hydroxylation does not occur. However, α-bromoketones were converted into α-hydroxyketones in the presence of KI. In the case of α,α′-diiodo ketones, α,α′-dihydroxyketones, which up to now have scarcely been reported, were obtained. This reaction affords a new, clean and convenient synthetic method for α-hydroxy- and α,α′- dihydroxyketones.

Full text of DOI:10.1016/j.tet.2005.01.010

Tetrahedron 61 (2005) 2453–2463
Photo-irradiation of a-halo carbonyl compounds: a novel
synthesis of a-hydroxy- and a,a0-dihydroxyketones
Wen Chai,a Akihiro Takeda,a Makoto Hara,a Shun-Jun Jib and C. Akira Horiuchia,
*
aDepartment of Chemistry, Rikkyo (St. Paul’s) University, Nishi-Ikebukuro, Toshima-Ku, Tokyo 171-8501, Japan
bDepartment of Chemistry and Chemical Engineering, Suzhou University, 1 Shizi St. Suzhou, Jiangsu 215006, People’s Republic of China
Received 1 November 2004; accepted 5 January 2005
Available online 26 January 2005
Abstract—The reaction of a-halo ketones (a-iodocycloalkanones, a-bromocycloalkanones, a-iodo-b-alkoxy esters, and a-iodoacyclic-
ketones) with irradiation under a high-pressure mercury lamp gave the corresponding a-hydroxyketones in good yields. For a-bromoketones,
it was found that a-hydroxylation does not occur. However, a-bromoketones were converted into a-hydroxyketones in the presence of KI. In
the case of a,a0-diiodo ketones, a,a0-dihydroxyketones, which up to now have scarcely been reported, were obtained. This reaction affords a
new, clean and convenient synthetic method for a-hydroxy- and a,a0-dihydroxyketones.
q 2005 Elsevier Ltd. All rights reserved.
1. Introduction
of ketones with [bis(trifluoroacetoxy)] iodobenzene and
trifluoroacetic acid in acetonitrile–water under acidic
conditions;9 and a-hydroxylation by treatment of their
enolate forms with [hydroxy(tosyloxy)iodo]benzene in
aqueous dimethyl sulfoxide at room temperature.10
In the synthesis of various natural products and pharmaco-
logically active compounds, a-hydroxycarbonyl com-
pounds are potential intermediates. Accordingly,
a-hydroxyketones synthesis is an important reaction.
a-Hydroxyketones are usually prepared by one of the
following methods: a-hydroxylation by treatment of their
enolate forms with a molybdenum peroxide reagent in
THF–hexane at K70 8C;1 transformation of the enamine
derivatives of ketones to a-hydroxy derivatives by
molecular oxygen;2 a-hydroxylation of silyl enol ethers
with m-chloroperbenzoic acid,3 or with certain other
oxidizing agents;4 reaction of an alkyllithium reagent with
carbon monoxide in the presence of dichloroarylmethane;5
and direct air oxidation of ketones with a bimetallic
palladium (II) complex in aqueous THF.6
During the course of our studies, we investigated some
novel photosynthetic reactions to transform ketone deriva-
tives into useful compounds. For example, the self-coupling
reaction of cyclic ketones gives the corresponding pinacol-
type compounds in good yields with a high-pressure
mercury lamp.11 a-Iodocycloalkanones, which were syn-
thesized by our laboratory by a new method, are important
as intermediates in organic synthesis.12 For these iodo
ketones which are unstable and sensitive to light, we have
already shown that the photo-dehydroiodination from
a-iodocycloalkanones in hexane affords a,b-unsaturated
ketones as major products, accompanied by photoreduced
products as by-products. In hexane containing a small
amount of water, the substituted product 2-hydroxy-
cycloalkanone was also obtained.13 In our previous paper,
we found that photo-cleavage of the carbon–carbon bond of
a-iodocycloalkanones giving u,u-dialkoxyalkanoic esters
in alcohol gave a-hydroxyketones as intermediates.14 In
order to increase the yield of a-hydroxyketones, we
undertook a closer inquiry into the reaction conditions.
Still earlier, we described that the irradiation of a-iodo- and
a,a0-diiodo ketones in solvents containing a small amount
of air gave the a-hydroxy- and a,a0-hydroxyketones under a
high-pressure mercury lamp.15,16 Herein, we report details
concerning a novel synthesis of a-hydroxy- and a,a0-
dihydroxyketones.
It is known that there has been considerable interest in
the development of direct methods for the synthesis of
a-hydroxyketones using non-toxic hypervalent iodine
reagents, which involve the following methods: reaction
of ketones with iodobenzene diacetate in the presence of
potassium hydroxide in methanol and then hydrolysis of the
dimethylacetals;7 oxidation of enol silyl ether of aceto-
phenone using the system iodosobenzene/boron trifluoride
etherate/water in methylene chloride at K40 8C;8 reaction
Keywords: Hydroxylation; Cyclododecanone; Halo ketone; a,a0-
Dihydroxyketone.
* Corresponding author. Tel./fax: C81 3 3985 2397;
e-mail addresses: horiuchi@rikkyo.ac.jp; cahoriuchi@nifty.com
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.01.010

2454
W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
Table 1. Photochemical reaction of 3-iodo-3,6-dialkylcyclohexane-1,2-diones (1–2) under air
Run
Substrate
Solvent
Time/h
Product (%)a
d0
a
b
c
d
1
2
3
4
5
6
7
8
9
10
1
1
1
1
1
2
2
2
2
2
MeOH
EtOH
1-PrOH
2-PrOH
n-Hex
MeOH
EtOH
1-PrOH
2-PrOH
n-Hex
4
4
4
4
4
2
2
2
2
2
0
0
0
0
0
0
0
25
19
0
0
0
t
2
0
0
0
0
0
0
0
0
4
5
0
0
10
13
16
14
t
42
35
34
56
28
47
31
34
41
6
23
16
16
18
Reaction conditions: substrate (15.7 mmol) in solvent (10 ml) was irradiated by a high-pressure mercury lamp (400 W) under air.
a Yields were determined from GLC.
2. Results and discussion
hydroxydiosphenol17,18 in buchu oil from the leaves of
Barosma betulina Bartl. (mountain buchu). The reaction
exhibits the possibility of a new synthetic method of
a-hydroxyketones from a-iodoketones. We investigated the
photo-irradiation of 2-iodocycloketones (3–8), and 2-iodo
cyclododecanone (7) was selected as a model compound to
investigate the synthesis of a-hydroxyketones from
a-iodoketones. These results are summarized in Table 2.
The irradiation of 3-iodo-3,6-dialkylcyclohexanediones
(1–2) in a solvent at room temperature under air atmosphere
with a 400 W mercury lamp for 2–4 h gave the correspond-
ing 3-hydroxy-3,6-dialkylcyclohexanediones (1d-2d) as
major products. These results are summarized in Table 1.
From these results, it was found that this reaction afforded
Table 2. Effects of some amines on photochemical reaction of a-iodoketone 7
Run
Solvent
Base (molar
equivalent)
Time/h
Product (%)a
a
b
c
d
e
1
2
3
4
5
6
7
8
Me2CO
n-Hex
c-Hex
PhH
Et2O
EtOAc
MeCN
THF
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
n-Hex
c-Hex
0
0
0
0
0
0
0
0
10
10
10
10
10
10
10
10
10
10
43
50
10
10
15
40
40
10
20
20
10
15
15
25
62
17
17
18
3
8
4
5
4
5
17
13
t
50
t
3
2
t
t
t
t
4
2
4
4
13
10
11
6
22
58
93
5
t
t
5
5
9
2
13
8
3
42
41
45
52
53
28
59
70
0
0
0
0
45
43
30
46
0
0
0
0
0
0
0
0
0
6
15
9
8
2
3
2
t
t
t
t
t
t
t
t
t
t
t
t
t
12
95
95
90
85
17
24
43
30
37
33
2
90
95
68
63
83
87
90
77
77
9
i-Pr2NH (1)
n-Pr3N (1)
Et2NH (1)
PhNMe2 (1)
C5H5N (1)
C5H5N (10)
C5H5N (50)
C4H5NH (1)
C4H5NH (10)
t-BuOK (1)
NaOH (1)
NH3 (1)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
Et3N (1)
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
t
t
10
16
16
11
9
7
t
t
4
t
3
9
t
2
t
t
12
t
t
t
t
t
7
t
2
7
t
t
t
PhH
Et2O
EtOAc
MeCN
THF
0
0
0
t
t
Reaction conditions: substrate (0.1 mmol) in solvent (10 ml) was irradiated by a high-pressure mercury lamp (400 W) under air.
a Yields were determined by GLC. tZtrace.

W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
2455
From runs 1–8, it was found that 2-hydroxycyclododeca-
none (7d) was obtained as a by-product. In the presence of
triethylamine (run 21), u-formylcarboxylic acid (7e) was
not obtained, and 2-hydroxycyclododecanone (7d) was
formed as the only product. From the results mentioned
above, we investigated the photo-irradiation of some
a-iodoketones. These results are summarized in Table 3.
The irradiation of a-iodo ketones (3–14) gave the
corresponding a-hydroxyketones (3d-14d) in good yields
(Scheme 1).
From runs 1–8 of Table 2, it was found that the ring-opening
product 7e was obtained as the major product. Kropp has
reported that the photobehaviors of alkyl iodides are
competing ionic and radical photobehaviors.19 In line with
the conception of Kropp, the irradiation of 7 gave not only
the reduced ketone 7b and the eliminated product 7c as the
products of radical photobehavior, but also the a-hydroxy-
ketone 7d and the ring-opening product 7e as the products of
ionic photobehavior (Fig. 1). In the case of photo-irradiation
in acetone (run 1, Table 2), the radical products are obtained
in much the same ratio as the ionic products. So, the photo-
irradiation of 7 in acetone is an ideal reaction to investigate
how to decrease the reduced ketone 7b and the ring-opening
product 7e.
As can be seen from Table 3, it was found that the reaction
containing triethylamine (molar equivalent) gave preferen-
tially the a-hydroxyketones. Thus, in order to discuss the
reactivity of the a-iodocyclicketones, it was compared with
that of the bromo derivatives. Under the some reaction
conditions as that of a-iodocyclicketones, the reaction of
a-bromo ketones did not give a-hydroxyketones, but the
irradiation of a-bromo ketones in the presence of KI
(0.1 mmol) gave the corresponding a-hydroxyketones as
major products (runs 3, 5, 8, 12, and 14). It was found
that the yields of a-hydroxy ketones were lower in the
case of the bromo ketones with KI. However, in the
case of non-occurrence of a-iodination, that is, a-
iodocamphor, this reaction cannot be applied to the
synthesis of a-hydroxycamphor. In order to overcome
this problem, we tried the reaction of a-bromocamphor
(280) with KI. As can be seen from Table 3 (runs 18–
22), it was found that a-hydroxycamphor was obtained
in good yields.
On the other hand, the ring-opening product 7e was obtained
as the final product of ionic photobehavior (Fig. 1). It is
considered that the a-hydroxyketone 7d is an intermediate
of the ionic photobehavior, and we investigated the
irradiation of 7d in acetone by a high-pressure mercury
lamp (400 W) under air. The reaction resulted in the
recovery of substrate 7d, and the ring-opening product
7e was not obtained (Scheme 2). The result suggests that
the presence of HI is vital to give the ring-opening
product 7e via a-hydroxyketone 7d. It seems that the
irradiation of 7 gave 7d as the final product of the ionic
photobehavior instead of 7e in the presence of an HI
scavenger.
According to Kropp’s report, it is noted that bases such
as Et3N or NH4OH are used as an HX scavenger in
photo-irradiation of alkyl halides.19 Based on the views of
Kropp, we investigated the reaction in the presence of
various bases to decrease the ring-opening product 7e (runs
In order to investigate the reaction pathway of the
hydroxylation for a-iodocycloalkanones in acetone contain-
ing triethylamine, photo-irradiation of 7 was carried out.
Table 3. Photochemical reaction of a-halo ketones in the presence of Et3N
Run
Substrate
X
n
Solvent
Et3N (molar equivalent) Time/h
Product (%)a
a
b
c
d
e
1
2
3
4
5
6
7
8
3
I
I
Br
I
Br
I
I
Br
I
I
I
Br
I
Br
I
I
I
Br
Br
Br
Br
Br
1
2
2
3
3
5
7
7
10
Me2CO
Me2CO
MeOH
Me2CO
MeOH
Me2CO
Me2CO
MeOH
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
Me2CO
MeOH
MeOH
EtOH
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
2
2
10
10
12
10
12
10
10
12
10
12
10
12
10
12
10
10
10
48
12
24
72
68
10
41
t
35
t
24
t
t
t
t
t
t
t
t
t
t
t
t
t
4
t
4
t
3
t
t
3
t
5
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
7
t
15
t
t
t
t
t
t
t
t
49
56
42
60
35
70
95
47
95
70
81
30
87
31
89c
92c
94c
85
62
52
86
85
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
4b
5
5b
6
7
7b
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
9
10
10b
11
11b
12
13
14
28b
28b
28b
28b
28b
(exo/endoZ40:60)c
(exo/endoZ40:60)c
(exo/endoZ33:67)c
(exo/endoZ43:57)c
(exo/endoZ43:57)c
t
t
t
t
t
t
t
Me2CO
MeCN
t
Reaction conditions: substrate (0.1 mmol) in solvent (10 ml) was irradiated by a high-pressure mercury lamp (400 W) under air.
a Yields were determined by GLC.
b KI (0.1 mmol) was used.
c Product ratio was determined from the peak area ratio of the NMR spectrum. tZtrace.

2456
W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
Scheme 1. Photo-irradiation of a-halo carbonyl compounds.
9–21, Table 2). It was found that amine bases such as
i-Pr2NH, Et2NH, PhNMe2, NH3, Et3N, and n-Pr3N
were effective. In the presence of Et3N (run 21),
u-formylcarboxylic acid (7e) was not obtained, and
2-hydroxycyclododecanone (7d) was formed as the only
product. In the presence of oxide bases, the radical product
7b was obtained as the major product (runs 18 and 19).
From these results, it is believed that the radical photo-
behavior is preferentially carried out in the presence of a
strong base such as NaOH (Scheme 3).
Figure 1. The photo-irradiation pathway of a-iodocyclododecanone (7).

W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
2457
a-hydroxyketone 7d depended on the quantity of Et3N. In
the absence of Et3N, a-hydroxyketone 7d was not obtained;
the reduced ketone 7b and ring-opening product 7e were
formed in 50 and 42% yields, respectively. As the
equivalent of Et3N increased, the reduced ketone 7b
decreased. When the reduced ketone 7b disappeared, the
ring-opening product 7e stated decreasing. Finally, a-hydro-
hydroxyketone 7d was formed as the only product (95%) in
the presence of above 1 molar equivalent of Et3N. It is
believed that Et3N has two important roles in this photo-
irradiation: first, Et3N makes the ionic photobehavior
become the main pathway; second, Et3N is an HI scavenger
to stop the synthetic process of the ring-opening product 7e.
To discuss the pathway from the caged cation IV to
hydroxyketone 7d in Figure 1, we consulted the experi-
mental results regarding the effect of water in our previous
paper. In Ji’s paper, it was found that a small amount of
water in alcohol is absolutely essential for forming the ring-
opening product, and hydroxyketone is a reactive inter-
mediate.14 In the irradiation of 7 in acetone containing Et3N,
it was found that the yield of hydroxyketone 7d did not
decrease in the presence of 0.6 ml H2O (Scheme 2). It is
believed that the water contained in acetone is a very
important agent to form hydroxyketones.
Scheme 2.
On the other hand, the direct photo-oxidation of triethyl-
amine with molecular oxygen20 is well known. Therefore,
we discussed the possibility of the electron transfer between
molecular oxygen and triethylamine in the photobehavior of
hydroxyketones (Fig. 1). In order to clarify this pathway,
oxidation of 7 with superoxide anion was carried out. In the
oxidation of 7 in acetone containing KO2 and 18-crown-6-
ether, hydroxyketone 7d was not obtained (Scheme 2). This
result denies for the direct attack of superoxide anion to give
hydroxyketone 7d. However, the result is not rule out the
attack of the ion-pair formation of molecular oxygen and
triethylamine. Therefore, the pathway from the caged cation
V to hydroxyketone 7d is possible.
Scheme 3.
For the results mentioned above, it was found that Et3N is
the best HX scavenger to give a-hydroxyketone derivatives.
In order to investigate the relationship between the yields of
products (7b, 7d, and 7e) and the equivalent of Et3N, the
irradiation of 2-iodocyclododecanone (7) in the presence of
Et3N was carried out (Fig. 2). It was found that the yield of
In order to investigate the reaction of a,a0-diiodo ketones,
the irradiation of a,a0-diiodo ketones (15–19, 22–23) was
carried out with a 400 W mercury lamp under air
Figure 2. Relation between molar equivalent of triethylamine and yields of products.

2458
W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
Table 4. Photochemical reaction of a-iodo- and a,a0-diiodoacyclicketone
Run
Substrate
R1
R2
Time (h)
Product (%)
1
2
3
4
5
6
7
8
15 (cis/transZ95/5)
16 (cis/transZ90/10)
17 (cis/transZ75/25)
18 (cis/transZ62/38)
Me
Et
n-C3H7
n-C4H9
Me
H2
H2
CH2–(CH2)2–CH2
CH2–(CH2)7–CH2
Me
Me
Ph
Me
Et
5
6
6
6
5
3
3
5
15f (47,cis/transZ50/50)a
16f (58,cis/transZ50/50)a
17f (65,cis/transZ50/50)a
18f (73,cis/transZ50/50)a
19f (70,cis/transZ50/50)a
20f (t)
n-C3H7
n-C4H9
n-C7H15
n-C3H7
n-C4H9
19 (cis/transZ54/46)
20
21
22
23
24
25
26
27
21f (t)
22f (82,cis/transZ87/13)a
23f (54,cis/transZ90/10)a
24d (65,syn/antiZ81/19)a
25d (62,syn/antiZ80/20)a
26d (72,syn/antiZ84/16)a
27d (75,syn/antiZ81/10)a
9
5
10
11
12
13
Me
Et
Me
Et
10
10
8
Ph
8
Reaction conditions: substrate (0.1 mmol) in acetone (10 ml) containing triethylamine (0.2 mmol) was irradiated by a high-pressure mercury lamp (400 W)
under air. Yields were determined by GLC.
a Isolated yields. Product ratio was determined from the peak area ratio of the NMR spectrum.
atmosphere in acetone containing Et3N (Table 4). It was
found that the corresponding a,a0-dihydroxy ketones
(15f-19f, 22f-23f) were obtained in good yields. In the
case of a-iodo-b-alkoxy esters (24–27), a-hydroxy-b-
alkoxy esters (24d-27d) were also obtained in good yields
(runs 10–13). However, the irradiation of the primary
a-iodo ketones (20, 21) did not give a,a0-dihydroxyketones
(20f, 21f) as major products.
carbonyl compounds (Table 6). The secondary a-iodo
carbonyl compounds (33–38) gave the corresponding
a-hydroxy-b-alkoxy alkanoic esters (33d–38d) in good
yields. As tertiary a-iodo carbonyl compounds, a-iodo-b-
alkoxy alkanoic esters 39 and 40 gave the corresponding
tertiary a-hydroxy carbonyl compounds 39d and 40d in 42
and 40% yield, respectively. On the basis of these results, it
was found that the yields of tertiary a-hydroxy carbonyl
compounds were lower than the yields of secondary
a-hydroxy carbonyl compounds.
Moreover, the irradiation of primary a-iodo ketone
derivatives (29–32) was carried out in acetone containing
Et3N (Table 5). It was found that the corresponding
a-hydroxycarbonyl compounds (29d–32d) were formed in
low yields (5–10%). From these results, it is considered that
the synthetic method is not applicable to form primary
a-hydroxyketones. Also, the photo-irradiation was investi-
gated using a-iodo-b-alkoxy alkanoic esters (33–40) as
secondary a-iodo carbonyl compounds or tertiary a-iodo
In conclusion, this method is very clean, simple, and
convenient for the synthesis of secondary a-hydroxy
carbonyl compounds and tertiary a-hydroxy carbonyl
compounds. It is particularly noteworthy that this
reaction affords a new synthetic method for a-hydroxy-
ketones, a,a0-dihydroxyketones and a-hydroxy-b-alkoxy
ester derivatives.
Table 5. Photochemical reaction of primary a-iodoketone derivatives (29–32)
Run
Substrate
Solvent
Et3N (equiv)
R
Time/h
Product (%)a
a
b
c
d
1
2
3
4
5
6
7
8
9
29
29
29
29
29
29
30
31
32
Acetone
MeOH
Et2O
Acetone
MeOH
Et2O
An
An
An
0
0
0
1
1
1
1
1
1
H
H
H
H
H
H
3
3
3
5
5
5
5
5
5
45
0
0
0
0
0
0
0
0
25
20
90
20
10
5
30
5
5
0
67
0
0
20
0
0
0
0
6
5
5
10
5
5
10
5
OMe
n-C4H9
n-C5H11
5
Reaction conditions: substrate (0.1 mmol) in solvent (10 ml) was irradiated by a high-pressure mercury lamp (400 W) under air.
a Yields were determined from GLC.

W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
Table 6. Photochemical reaction of a-iodo-b-alkoxyl alkanoic ester (33–40)
2459
Run
Substrate
R1
R2
R3
Time/h
Product (%)a
1
2
3
4
5
6
7
8
33
34
35
36
37
38
39
40
Me
Et
n-Pr
Me
Et
n-Pr
Me
Et
Me
Me
Me
Et
Et
Et
H
H
H
H
H
H
Me
Me
10
10
12
10
10
10
8
33d (52)
34d (56)
35d (61)
36d (60)
37d (62)
38d (71)
39d (42)
40d (40)
Et
Et
8
Reaction conditions: substrate (0.1 mmol) in acetone (10 ml) containing triethylamine (0.1 mmol) was irradiated by a high-pressure mercury lamp (400 W)
under air.
a Isolated yields.
3. Experimental
3.1. General procedure
(s, 1H), 2.64–2.41 (m, 1H), 2.35 (t, 1H), 2.09-2.04 (m, 2H),
1.95 (s, 3H) and 1.26 (d, 3H); 13C NMR (CDCl3) d(ppm)Z
197.3, 141.2, 131.8, 72.7, 35.3, 29.7, 27.7 and 17.1; MS (EI)
m/z 156 (MC), 138 ([MKH2O]C), 125, 113, 98, 95, 70, 58
and 43; MS (CI) m/z 157 ([MCH]C).
IR spectra were recorded on a Jasco FT-IR 230 spec-
1
trometer. H and 13C NMR spectra were measured using a
3.2.2. 3-Hydroxy-3-methyl-6-isopropylcyclohexane-1,2-
dione (2d). Colorless needles; mp 71–72 8C; IR (KBr)Z
JEOL GSX 400 Model spectrometer in deuteriochloroform
solutions with tetramethylsilane used as an internal
standard.
1
3447, 1670 and 1637 cmK1; H NMR (CDCl3) d(ppm)Z
5.28 (s, 1H), 3.23 (s, 1H), 3.19–3.11 (m, 1H), 2.40–2.31 (m,
2H), 2.13–1.95 (m, 2H), 1.34 (s, 3H) and 1.07 (dd, 6H); 13C
NMR (CDCl3) d(ppm)Z197.9, 140.6, 139.7, 72.6, 35.3,
28.1, 24.3, 20.7 and 19.5; MS (EI) m/z 184 (MC), 166
([MKH2O]C), 124, 123, 109, 83, 69, 55 and 43; MS (CI)
m/z 185 ([MCH]C). Found: m/z 184.110. Calcd for
C10H16O3: M, 184.110.
GC–MS (EI) analyses were performed on a Shimazu
GCMS-QP5050 with an ionizing energy of 70 eV. CIMS
(i-butane reagent gas) were recorded on a Shimazu GCMS-
QP5050 with an ionizing energy of 300 eV. The high-
resolution mass spectra (EI) were performed on a JEOL
JMS-GCMATE II with an ionizing energy of 70 eV.
3.2.3. 2-Hydroxycycloheptanone (4d).21 Pale-yellow oil;
IR (NaCl)Z3469 (O–H) and 1699 (C]O) cmK1; 1H NMR
(CDCl3) d(ppm)Z4.29 (dt, 1H, JZ6.2, 2.1 Hz, CHOH),
3.86 (brd, 1H, CHOH), 2.72 (dddd, 1H, JZ0.9, 2.2, 4.8,
7.1 Hz, C(O)CHH), 2.47 (ddd, 1H, JZ3.8, 11.3, 18.2 Hz,
C(O)CHH), 2.01–2.09 (m, 1H), 1.74–1.93 (m, 3H), 1.54–
1.73 (m, 3H) and 1.29–1.40 (m, 1H); 13C NMR (CDCl3)
d(ppm)Z213.2, 77.2, 40.0, 33.6, 29.4, 26.5 and 23.2; MS
(EI) m/z 128 (MC), 110 ([MKH2O]C), 99, 81, 57 and 44;
MS (CI) m/z 129 ([MCH]C).
3.2. Photo-irradiation of a-halo ketones (1–14, 28)
Typical procedure for the irradiation of a-iodo ketones. A
mixture of a-iodo ketone (0.10 mmol) and acetone (10 ml)
containing triethylamine (0.10 mmol) was irradiated by a
400 W high-pressure mercury lamp under air for 10 h. After
the irradiation was completed, the mixture was concen-
trated, poured into water, and extracted with diethyl ether
(30 ml). The ethereal solution was washed with a saturated
solution of sodium thiosulfate (2!2.0 ml), saturated aq
NaCl (2!2.0 ml) and water (2!2.0 ml). The ethereal
solutions were dried over Na2SO4 and concentrated in a
vacuum. The resulting oil was chromatographed on silica
gel. Elution with hexane–ether (3:1) gave isolated com-
3.2.4. 2-Hydroxycyclooctanone (5d).21 Pale-yellow oil; IR
1
(NaCl)Z3475 (O–H) and 1701 (C]O) cmK1; H NMR
(CDCl3) d(ppm)Z4.19 (dd, 1H, JZ1.9, 4.3 Hz, CHOH),
3.79 (brs, 1H, CHOH), 2.71 (dt, 1H, JZ2.6, 8.5 Hz,
C(O)CHH), 2.30–2.45 (m, 2H), 1.91–2.08 (m, 2H), 1.62–
1.87 (m, 4H), 1.32–1.45 (m, 2H) and 0.85–0.97 (m, 1H); 13C
NMR (CDCl3) d(ppm)Z217.6, 76.1, 37.4, 29.2, 28.3, 25.7,
24.8 and 22.1; MS (EI) m/z 142 (MC), 124 ([MKH2O]C),
113, 98, 81, 57 and 41; MS (CI) m/z 143 ([MCH]C).
pounds. These compounds were identified by 1H NMR, 13
NMR, IR and GC–MS.
C
Typical procedure for the irradiation of a-bromo ketones. A
mixture of a-bromo ketone (0.10 mmol), KI (0.10 mmol)
and triethylamine (0.10 mmol) in acetone (10 ml) was
irradiated by a 400 W high-pressure mercury lamp in the
presence of air for 12 h.
3.2.5. 2-Hydroxycyclodecanone (6d).21 Pale-yellow oil; IR
1
(NaCl)Z3463 (O–H) and 1699 (C]O) cmK1; H NMR
3.2.1. 3-Hydroxy-3,6-dimethylcyclohexane-1,2-dione
(1d). Pale-yellow oil; IR (NaCl)Z3447, 1675 and
(CDCl3) d(ppm)Z4.23 (d, 1H, JZ4.0 Hz, CHOH), 3.94
(brs, 1H, CHOH), 3.15 (ddd, 1H, JZ3.6, 8.1, 12.2 Hz,
C(O)CHH), 2.29 (dt, 1H, JZ1.1, 4.6 Hz, C(O)CHH),
1
1647 cmK1; H NMR (CDCl3) d(ppm)Z5.78 (s, 1H), 3.18

2460
W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
2.04–2.27 (m, 3H), 1.21–1.72 (m, 10H) and 0.98–1.15 (m,
1H); 13C NMR (CDCl3) d(ppm)Z214.5, 76.8, 35.2, 29.3,
26.1, 25.0, 23.3, 22.9, 22.5 and 20.7; MS (EI) m/z 170 (MC),
152 ([MKH2O]C), 134 ([MKH2O]C), 111, 98, 81, 57 and
41; MS (CI) m/z 171 ([MCH]C).
(NaCl)Z3415 (O–H), 1718 (C]O) cmK1 1H NMR
;
(CDCl3) d(ppm)Z4.22 (dd, 1H, JZ3.9, 7.2 Hz, CHOH),
2.21 (s, 3H, C(O)CH3), 1.35–1.86 (m, 4H) and 0.96 (t, 3H,
JZ7.5 Hz, CH2CH3); 13C NMR (CDCl3) d(ppm)Z210.5,
76.8, 35.5, 25.2, 17.8 and 13.6; MS (EI) m/z 117 ([MC
H]C), 97, 87, 73, 55 and 43.
3.2.6. 2-Hydroxycyclododecanone (7d).21 Pale-yellow oil;
1
IR (NaCl) 3418 (O–H) and 1714 (C]O) cmK1; H NMR
3.2.12. 3-Hydroxy-2-heptanone (13d).24 Pale-yellow oil;
(CDCl3) d(ppm)Z4.23 (brs, 1H), 3.94 (brs, 1H), 3.01 (m,
1H), 2.05–2.31 (m, 2H), 1.48–1.68 (m, 1H), 1.05–1.45 (m,
15H) and 0.73–0.91 (m, 1H); 13C NMR (CDCl3) d(ppm)Z
212.9, 76.6, 34.3, 30.7, 26.1, 24.9, 22.6, 22.5, 21.9, 21.6,
18.8 and 15.6; MS (EI) m/z 198 (MC), 180, 162, 149, 133,
111, 95, 82 and 55; MS (CI) m/z 199 ([MC1]C).
IR (NaCl)Z3421 (O–H), 1718 (C]O) cmK1 1H NMR
;
(CDCl3) d(ppm)Z4.18 (dd, 1H, JZ4.4, 7.3 Hz, CHOH),
3.70 (brs, 1H, CHOH), 2.20 (s, 3H, C(O)CH3), 1.78–1.88
(m, 1H), 1.51–1.61 (m, 1H), 1.29–1.48 (m, 2H) and 0.92 (t,
3H, JZ6.8 Hz, CH2CH3); 13C NMR (CDCl3) d(ppm)Z
210.4, 77.0, 33.3, 28.6, 25.2, 22.6 and 13.9; MS (EI) m/z 130
(MC), 112 ([MKH2O]C), 97 ([MKCH3]C), 87, 69, 57 and
41.
3.2.7. 2-Hydroxycyclopentadecanone (8d). Pale-yellow
1
oil; IR (NaCl)Z3477 (O–H) and 1708 (C]O) cmK1; H
NMR (CDCl3) d(ppm)Z4.25 (q, 1H, JZ1.9 Hz, CHOH),
3.62 (d, 1H, JZ2.3 Hz, CHOH), 2.61 (dt, 1H, JZ8.2,
3.9 Hz, C(O)CHH), 2.33 (dt, 1H, JZ6.4, 3.0 Hz,
C(O)CHH), 1.54–1.93 (m, 3H) and 1.12–1.49 (m, 21H);
13C NMR (CDCl3) d(ppm)Z212.7, 76.0, 36.8 (2C), 32.6,
27.2, 26.5, 26.4, 26.1 (2C), 25.9 (2C), 25.8, 22.2 and 21.9;
MS (EI) m/z 240 (MC), 222 ([MKH2O]C), 166, 152, 138,
124, 110, 96, 82 and 55; HRMS found: m/z 240.2119 [M]C.
Calcd for C15H28O2: M, 240.2089.
3.2.13. 3-Hydroxy-2-undecanone (14d).25 Pale-yellow oil;
IR (NaCl)Z3475 (O–H), 1718 (C]O) cmK1 1H NMR
,
(CDCl3) d(ppm)Z4.19 (dt, 1H, JZ7.2, 4.7 Hz, CHOH),
3.53 (d, 1H, JZ4.3 Hz, CHOH), 2.20 (s, 3H, C(O)CH3),
1.78–1.88 (m, 1H), 1.41–1.60 (m, 2H), 1.24–1.37 (m, 11H)
and 0.88 (t, 3H, JZ6.9 Hz, CH2CH3); 13C NMR (CDCl3)
d(ppm)Z210.0, 76.7, 33.5, 31.8, 29.4, 29.3, 29.1, 25.1,
24.7, 22.6 and 14.0; MS (EI) m/z 186 (MC), 143, 125, 111,
97, 83, 69, 55 and 43.
3.2.8. 2-Hydroxytetralone (9d).22 Pale-yellow oil; IR
3.3. Photo-irradiation of a,a0-diiodo ketones (15–23)
(NaCl)Z3476 (O–H), 1685 (C]O) cmK1 1H NMR
;
(CDCl3) d(ppm)Z8.04 (dd, 1H, JZ1.3, 5.3 Hz), 7.51 (dt,
1H, JZ1.0, 5.2 Hz), 7.33 (t, 1H, JZ5.6 Hz), 7.26 (d, 1H,
JZ5.5 Hz), 4.38 (dd, 1H, JZ4.0, 9.5 Hz, CHOH), 4.05 (brs,
1H, CHOH), 3.14 (ddd, 1H, JZ3.9, 8.8, 11.8 Hz,
CH(OH)CHH), 3.02 (ddd, 1H, JZ1.8, 3.1, 11.7 Hz,
CH(OH)CHH), 2.52 (dddd, 1H, JZ1.9, 3.1, 3.9, 5.2 Hz,
C(OH)CH2CHH) and 2.03 (dq, 1H, JZ3.4, 9.2 Hz,
C(OH)CH2CHH); 13C NMR (CDCl3) d(ppm)Z199.8,
144.3, 134.5, 130.8, 129.0, 127.8, 127.0, 74.1, 32.0 and
27.9; MS (EI) m/z 162 (MC), 144 ([MKH2O]C), 133, 118,
103, 90, 77, 63 and 51; MS (CI) m/z 163 ([MCH]C).
Typical procedures. A mixture of a,a0-diiodo ketone
(0.10 mmol) and triethylamine (0.20 mmol) in acetone
(10 ml) was irradiated by a high-pressure mercury lamp in
the presence of air. After the irradiation was completed, the
mixture was concentrated, poured into water, and extracted
with diethyl ether (30 ml). The ethereal solution was washed
with a saturated solution of sodium thiosulfate (2!2.0 ml),
saturated aq NaCl (2!2.0 ml) and water (2!2.0 ml). The
ethereal solution was dried over Na2SO4 and concentrated
in a vacuum. The resulting oil was chromatographed on
silica gel. Elution with hexane–ether (3:1) gave isolated
compounds. These compounds were identified by 1H NMR,
13C NMR, IR and GC–MS.
3.2.9. 2-Hydroxy-1-phenyl-1-propanone (10d).10 Pale-
yellow oil; IR (NaCl)Z3448 (O–H), 1685 (C]O) cmK1
;
1H NMR (CDCl3) d(ppm)Z7.93 (dt, 2H, JZ6.5, 1.3 Hz),
7.62 (tt, 1H, JZ1.2, 12.6 Hz), 7.51 (tt, 2H, JZ1.3, 12.8 Hz),
5.17 (dq, 1H, JZ3.6, 7.0 Hz, CHOH), 3.80 (brd, 1H,
CHOH), 1.46 (d, 3H, JZ7.0 Hz, CH(OH)CH3); 13C NMR
(CDCl3) d(ppm)Z202.4, 134.0, 133.2, 128.9 (2C), 128.6
(2C), 69.3 and 22.3; MS (EI) m/z 135 ([MKCH3]C), 115,
105 ([MKC(OH)CH3]C), 91, 77, 63 and 51.
3.3.1. 3,5-Dihydroxy-4-heptanone (cis/transZ50/50, 16f).
Colorless oil, IR (NaCl)Z3397 (O–H), 1718 (C]O) cmK1
;
1H NMR (CDCl3) d(ppm)Z4.41 (dd, 2H, JZ4.0, 6.9 Hz,
CHOH), 4.37 (dd, 2H, JZ3.9, 7.9 Hz, CHOH), 3.33 (brs,
2H!2, CHOH), 1.85–1.99 (m, 2H!2), 1.65 (dquint, 2H,
JZ14.7, 6.9 Hz), 1.63 (dquint, 2H, JZ14.2, 7.0 Hz), 0.98
(t, 6H, JZ7.0 Hz, CH2CH3) and 0.97 (t, 6H, JZ7.0 Hz,
CH2CH3); 13C NMR (CDCl3) d(ppm)Z214.3, 213.9, 75.8,
74.6, 27.4, 26.7, 9.3 and 8.8; MS (EI) m/z 128 ([MK
H2O]C), 117, 100, 88, 70, 59 and 41; HRMS found: m/z
147.0987 [MCH]C. Calcd for C7H15O3: MCH, 147.1021.
3.2.10. 2-Hydroxy-1-phenyl-1-butanone (11d).23 Pale-
yellow oil; IR (NaCl)Z3475 (O–H), 1685 (C]O) cmK1
;
1H NMR (CDCl3) d(ppm)Z7.91 (dt, 2H, JZ7.4, 1.6 Hz),
7.62 (tt, 1H, JZ1.1, 7.7 Hz), 7.51 (tt, 2H, JZ2.6, 11.5 Hz),
5.07 (dt, 1H, JZ3.9, 7.6 Hz, CHOH), 3.72 (d, 1H, JZ
6.0 Hz, CHOH), 1.56–1.69 (m, 2H, CH(OH)CH2) and 0.94
(t, 3H, JZ7.2 Hz, CH2CH3); 13C NMR (CDCl3) d(ppm)Z
202.1, 133.9, 133.7, 128.9 (2C), 128.5 (2C), 73.9, 28.8
and 8.8; MS (EI) m/z 135 ([MKCH2CH3]C), 115, 105
([MKC(OH)CH2CH3]C), 91, 77, 59 and 51.
3.3.2. 4,6-Dihydroxy-5-nonanone (cis/transZ50/50,
17f).26 Colorless oil, IR (NaCl)Z3421 (O–H), 1718
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.37 (dd, 2H,
JZ3.1, 6.4 Hz, CHOH), 4.35 (dd, 2H, JZ3.9, 7.8 Hz,
CHOH), 3.38 (brs, 2H!2, CHOH), 1.64–1.81 (m, 2H!2),
1.27–1.54 (m, 2H!2), 0.88 (t, 6H, JZ6.2 Hz, CH2CH3)
and 0.87 (t, 6H, JZ6.9 Hz, CH2CH3), 13C NMR (CDCl3)
d(ppm)Z214.7, 214.2, 74.5, 73.6, 36.2, 35.6, 18.3, 18.1,
3.2.11. 3-Hydroxy-2-hexanone (12d).6 Pale-yellow oil; IR

W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
2461
13.7 and 13.6; MS (EI) m/z 156 ([MKH2O]C), 145, 114,
102, 84, 73, 55 and 43; HRMS found: m/z 175.1292 [MC
H]C. Calcd for C9H19O3: MCH, 175.1334.
thiosulfate (2!2.0 ml), saturated aq NaCl (2!2.0 ml) and
water (2!2.0 ml). The ethereal solution was dried over
Na2SO4 and concentrated in a vacuum. The resulting oil was
chromatographed on silica gel. Elution with hexane–ether
(3:1) gave isolated compounds. These compounds were
identified by 1H NMR, 13C NMR, IR and GC–MS.
3.3.3. 5,7-Dihydroxy-6-undecanone (cis/transZ50/50,
18f). Colorless oil, IR (NaCl)Z3421 (O–H), 1718
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.44 (dd, 2H,
JZ3.6, 8.5 Hz, CHOH), 4.41 (dd, 2H, JZ3.8, 8.0 Hz,
CHOH), 3.42 (brs, 2H, CHOH), 3.23 (brs, 2H, CHOH),
1.77–1.92 (m, 2H!2), 1.51–1.61 (m, 2H!2), 1.30–1.48
(m, 2H!2) and 0.92 (t, 6H, JZ7.0 Hz, CH2CH3); 13C NMR
(CDCl3) d(ppm)Z214.7, 214.2, 74.8, 73.8, 34.1, 33.4, 27.2,
26.7, 22.4, 21.1, 14.2 and 13.9; MS (EI) m/z 184 ([MK
H2O]C), 173 ([MKCH2CH3]C), 128, 116, 98, 87, 69, 57
and 41; HRMS found: m/z 203.1757 [MCH]C. Calcd for
C11H23O3: MCH, 203.1647.
3.4.1. Ethyl syn-3-methoxy-2-hydroxy butanonate (24d).
Pale-yellow oil, IR (NaCl)Z3482 (O–H), 1735
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.31 (dq, 1H,
JZ10.1, 7.1 Hz, C(O)OCHHCH3), 4.25 (dq, 1H, JZ10.1,
7.1 Hz, C(O)OCHHCH3), 4.03 (dd, 1H, JZ2.1, 7.7 Hz,
CHOH), 3.73 (dq, 1H, JZ2.1, 6.1 Hz, CH(OH)CH), 3.32 (s,
3H, CH3O), 2.95 (d, 1H, JZ7.7 Hz, CHOH), 1.31 (t, 3H,
JZ7.1 Hz, C(O)OCH2CH3), 1.28 (d, 3H, JZ6.1 Hz,
CH(OH)CHCH3); 13C NMR (CDCl3) d(ppm)Z173.0,
77.3, 74.1, 61.5, 56.9, 14.8 and 14.2; MS (EI) m/z 163
([MCH]C), 147, 131, 119, 104, 89, 76, 59 and 43; HRMS
found: m/z 162.0809 [M]C. Calcd for C7H14O4: M,
162.0892.
3.3.4. 2,4-Dihydroxy-3-undecanone (cis/transZ50/50,
19f). Pale-yellow oil, IR (NaCl)Z3409 (O–H), 1718
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.52 (dd, 2H,
JZ7.2, 3.2 Hz, CHOH); 4.47 (dd, 2H, JZ3.8, 7.9 Hz,
CHOH), 3.99 (brs, 2H!2, CHOH), 1.76–1.90 (m, 1H!2),
1.51–1.67 (m, 1H!2), 1.41 (d, 3H!2, JZ6.5 Hz, CH3-
CH(OH)), 1.22–1.35 (m, 10H!2) and 0.88 (t, 3H!2, JZ
7.4 Hz, CH2CH3); 13C NMR (CDCl3) d(ppm)Z214.8,
214.5, 74.6, 73.7, 70.9, 70.2, 34.2, 33.7, 31.8, 31.7, 29.3
(2C), 29.2 (2C), 25.1, 24.9, 22.7, 22.6, 20.3, 19.8, 14.2 and
14.1; MS (EI) m/z 173 ([MKCH2CH3]C), 158, 141, 129,
111, 98, 83, 69, 55 and 43; HRMS found: m/z 203.1650
[MCH]C. Calcd for C11H23O3: MCH, 203.1647.
3.4.2. Ethyl anti-3-methoxy-2-hydroxy butanonate (24d).
Pale-yellow oil, IR (NaCl)Z3463 (O–H), 1735
1
(C]O) cmK1: H NMR (CDCl3) d(ppm)Z4.32 (dd, 1H,
JZ3.8, 5.6 Hz, CHOH), 4.27 (dq, 2H, JZ3.5, 7.1 Hz,
C(O)OCH2CH3), 3.65 (dq, 1H, JZ3.9, 6.5 Hz,
CH(OH)CH), 3.41 (s, 3H, CH3O), 2.98 (brd, 1H, CHOH),
1.32 (t, 3H, JZ7.1 Hz, C(O)OCH2CH3), 1.17 (d, 3H, JZ
6.5 Hz, CH(OH)CHCH3); 13C NMR (CDCl3) d(ppm)Z
172.6, 78.2, 72.6, 61.7, 56.9, 14.2 and 14.0, MS (EI) m/z 162
(MC), 147, 131, 119, 104, 89, 76, 59 and 43. HRMS found:
m/z 162.0809 [M]C. Calcd for C7H14O4: M, 162.0892.
3.3.5. cis-2,7-Dihydroxycycloheptanone (22f).27 Colorless
needles; mp 83–85 8C; IR (KBr)Z3413 (O–H), 1708
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.28 (dd, 2H,
3.4.3. Ethyl syn-3-ethoxy-2-hydroxy butanonate (25d).
Pale-yellow oil, IR (NaCl)Z3504 (O–H), 1735
JZ3.9, 9.6 Hz, CHOH), 3.45 (brs, 2H, CHOH), 2.04–2.18
(m, 2H), 1.87–1.96 (m, 2H), 1.69–1.79 (m, 2H) and 1.56–
1.66 (m, 2H); 13C NMR (CDCl3) d(ppm)Z214.6, 76.7 (2C),
32.5 (2C) and 27.1 (2C); MS (EI) m/z 144 (MC), 126 ([MK
H2O]C), 115, 97, 85, 70, 57 and 41; HRMS found: m/z
144.0763 [M]C. Calcd for C7H12O3: M, 144.0789.
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.29 (dq, 1H,
JZ10.1, 7.0 Hz, C(O)OCHHCH3), 4.25 (dq, 1H, JZ10.1,
7.0 Hz, C(O)OCHHCH3), 4.03 (d, 1H, JZ3.5, 6.2 Hz,
CHOH), 3.83 (dq, 1H, JZ3.5, 6.2 Hz, CH(OH)CH), 3.60
(dq, 1H, JZ9.0, 7.0 Hz, CH3CHHO), 3.36 (dq, 1H, JZ9.0,
7.0 Hz, CH3CHHO), 2.98 (brs, 1H, CHOH), 1.31 (t, 3H, JZ
7.0 Hz, C(O)OCH2CH3), 1.28 (d, 3H, JZ6.2 Hz,
CH(OH)CHCH3), 1.14 (t, 3H, JZ7.0 Hz, CH3CH2O); 13C
NMR (CDCl3) d(ppm)Z173.0, 75.5, 74.2, 64.6, 61.4, 15.7,
15.2 and 14.1; MS (EI) m/z 151, 131, 121, 105, 91, 77, 65
and 51; HRMS found: m/z 176.1016 [M]C. Calcd for
C8H16O4: M, 176.1049.
3.3.6. cis-2,12-Dihydroxycyclododecanone (23f). Color-
1
less oil, IR (NaCl)Z3384 (O–H), 1718 (C]O) cmK1; H
NMR (CDCl3) d(ppm)Z4.59 (ddd, 2H, JZ4.7, 7.2,
10.2 Hz, CHOH), 3.37 (brs, 2H, CHOH), 1.86–2.06 (m,
2H), 1.58–1.83 (m, 2H), 1.23–1.53 (m, 10H), 1.06–1.17 (m,
2H) and 0.92–1.03 (m, 2H); 13C NMR (CDCl3) d(ppm)Z
212.7, 73.3, 72.6, 32.0, 30.7, 25.1, 23.4, 23.1, 22.8, 22.4,
21.7 and 19.8; MS (EI) m/z 214 (MC), 183, 155, 147, 135,
112, 98, 95, 81, 55 and 41; CI-MS (m/z): 215 ([MCH]C);
HRMS found: m/z 214.1597 [M]C. Calcd for C12H22O3: M,
214.1569.
3.4.4. Ethyl anti-3-ethoxy-2-hydroxy butanonate (25d).
Pale-yellow oil, IR (NaCl)Z3461 (O–H), 1735
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.29–4.33 (m,
1H, CHOH), 4.27 (dq, 2H, JZ1.9, 7.2 Hz, C(O)OCH2CH3),
3.74 (dq, 1H, JZ3.1, 6.5 Hz, CH(OH)CH), 3.59 (dq, 1H,
JZ9.1, 7.0 Hz, CH3CHHO), 3.54 (dq, 1H, JZ9.1, 7.0 Hz,
CH3CHHO), 2.90 (brd, 1H, JZ5.6 Hz, CHOH), 1.31 (t, 3H,
JZ7.2 Hz, C(O)OCH2CH3), 1.21 (t, 3H, JZ7.0 Hz,
CH3CH2O), 1.16 (d, 3H, JZ6.5 Hz, CH(OH)CHCH3); 13C
NMR (CDCl3) d(ppm)Z172.6, 76.4, 72.9, 64.6, 61.6, 15.4,
14.7 and 14.2; MS (EI) m/z 151, 131, 121, 105, 91, 77, 65
and 51.
3.4. Photo-irradiation of a-iodo-b-alkoxy alkanoic ester
(24–27, 33–40)
Typical procedures. A mixture of a-iodo-b-alkoxy alkanoic
ester (0.10 mmol) and triethylamine (0.10 mmol) in acetone
(10 ml) was irradiated by a high-pressure mercury lamp in
the presence of air for 10 h. After the irradiation was
completed, the mixture was concentrated, poured into water,
and extracted with diethyl ether (30 ml). The ethereal
solution was washed with a saturated solution of sodium
3.4.5. Ethyl syn-3-phenyl-3-methoxy-2-hydroxy propio-
nate (26d). Pale-yellow oil, IR (NaCl)Z3488 (O–H), 1735

2462
W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z7.31–7.39 (m,
5H, C6H5), 4.55 (d, 1H, JZ3.2 Hz, CHOH), 4.28 (dq, 1H,
JZ10.6, 7.0 Hz, C(O)OCHHCH3), 4.25 (d, 1H, JZ3.2 Hz,
CH(OH)CHOCH3), 4.22 (dq, 1H, JZ10.6, 7.0 Hz,
C(O)OCHHCH3), 3.28 (s, 3H, CH3O), 3.02 (d, 1H, JZ
7.5 Hz, CHOH) and 1.27 (t, 3H, JZ7.0 Hz, C(O)OCH2-
CH3); 13C NMR (CDCl3) d(ppm)Z172.1, 137.0, 128.3
(2C), 128.2, 127.3 (2C), 83.9, 74.9, 61.7, 57.4 and 14.1; MS
(EI) m/z 176 ([MKOCH3KOH]C), 151, 131, 121, 105, 91,
77, 65 and 51; MS (CI) m/z 225 ([MCH]C).
CHOH), 3.81 (s, 3H, C(O)OCH3), 3.72 (d, 2H, JZ3.8 Hz,
CH(OH)CH2), 3.57 (dq, 1H, JZ9.6, 7.0 Hz, CH3CHHO),
3.53 (dq, 1H, JZ9.6, 7.0 Hz, CH3CHHO), 3.05 (brs, 1H,
CHOH) and 1.19 (t, 3H, JZ7.0 Hz, CH3CH2O); 13C NMR
(CDCl3) d(ppm)Z173.1, 71.6, 70.8, 67.2, 52.6 and 14.9;
MS (EI) m/z 115 ([MKOCH3]C), 105, 90, 71, 59 and 43;
HRMS found: m/z 148.0733 [M]C. Calcd for C6H12O4: M,
148.0736.
3.4.11. Methyl 3-n-propyroxy-2-hydroxy propionate
(35d). Pale-yellow oil, IR (NaCl)Z3475 (O–H), 1751
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.32 (brs, 1H,
3.4.6. Ethyl anti-3-phenyl-3-methoxy-2-hydroxy propio-
nate (26d). Pale-yellow oil, IR (NaCl)Z3482 (O–H), 1735
CHOH), 3.80 (s, 3H, C(O)OCH3), 3.72 (d, 2H, JZ3.8 Hz,
CH(OH)CH2), 3.47 (dt, 1H, JZ9.3, 7.5 Hz, CH3CH2-
CHHO), 3.41 (dt, 1H, JZ9.3, 7.5 Hz, CH3CH2CHHO),
3.09 (brd, 1H, CHOH), 1.58 (sextet, 2H, JZ7.5 Hz,
CH3CH2CH2O) and 0.89 (t, 3H, JZ7.5 Hz, CH3CH2CH2-
O); 13C NMR (CDCl3) d(ppm)Z173.1, 73.4, 71.8, 70.8,
52.5, 22.6 and 10.4; MS (EI) m/z 133 ([MKCH2CH3]C),
119 ([MK(CH2)2CH3]C), 103, 90, 73, 61 and 43; HRMS
found: m/z 162.0863 [M]C. Calcd for C7H14O4: M,
162.0892.
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z7.27–7.38 (m,
5H, C6H5), 4.53 (d, 1H, JZ4.4 Hz, CHOH), 4.23 (d, 1H,
JZ4.4 Hz, CH(OH)CH), 4.19 (dq, 1H, JZ12.7, 7.0 Hz,
C(O)OCHHCH3), 4.11 (dq, 1H, JZ12.7, 7.0 Hz,
C(O)OCHHCH3), 3.31 (s, 3H, CH3O), 3.17 (d, 1H, JZ
7.5 Hz, CHOH), 1.17 (t, 3H, JZ6.8 Hz, C(O)OCH2CH3);
13C NMR (CDCl3) d(ppm)Z171.6, 136.1, 128.1 (2C),
128.0, 127.2 (2C), 84.3, 74.0, 61.2, 57.2 and 13.8; MS (EI)
m/z 192 ([MKOCH3]C), 176 ([MKOCH3KOH]C), 151,
131, 121, 105, 91, 77, 65 and 51; MS (CI) m/z 225 ([MC
H]C).
3.4.12. Ethyl 3-methoxy-2-hydroxy propionate (36d).
Pale-yellow oil, IR (NaCl)Z3461 (O–H), 1739
3.4.7. Ethyl syn-3-phenyl-3-ethoxy-2-hydroxy propio-
nate (27d). Pale-yellow oil, IR (NaCl)Z3496 (O–H),
(C]O) cmK1 1H NMR (CDCl3) d(ppm)Z4.30 (t, 1H,
;
JZ3.6 Hz, CHOH), 4.27 (dq, 2H, JZ1.1, 7.0 Hz,
C(O)OCH2CH3), 3.69 (dd, 2H, JZ1.1, 3.8 Hz,
CH(OH)CH2), 3.39 (s, 3H, CH3O), 3.25 (brs, 1H, CHOH)
and 1.31 (t, 3H, JZ7.0 Hz, C(O)OCH2CH3); 13C NMR
(CDCl3) d(ppm)Z172.7, 74.0, 70.7, 61.8, 59.5 and 14.2;
MS (EI) m/z 148 (MC), 130 ([MKH2O]C), 118, 105, 85,
75, 59 and 45; HRMS found: m/z 148.0735 [M]C. Calcd for
C6H12O4: M, 148.0736.
1735 (C]O) cmK1 1H NMR (CDCl3) d(ppm)Z7.34–
;
7.41 (m, 5H, C6H5), 4.67 (d, 1H, JZ3.2 Hz, CHOH), 4.26
(dq, JZ10.6, 7.0 Hz, C(O)OCHHCH3), 4.23 (d, 1H, JZ
3.2 Hz, CH(OH)CH), 4.22 (dq, 1H, JZ10.6, 7.0 Hz,
C(O)OCHHCH3), 3.50 (dq, 2H, JZ9.5, 7.0 Hz,
CH3CH2O), 3.09 (d, 1H, JZ7.3 Hz, CHOH), 1.27 (t, 3H,
JZ7.0 Hz, C(O)OCH2CH3), 1.16 (t, 3H, JZ7.1 Hz,
CH3CH2O); 13C NMR (CDCl3) d(ppm)Z172.1, 137.8,
128.2 (2C), 128.1, 127.3 (2C), 127.2, 81.8, 75.1, 64.9, 61.5,
14.9 and 14.1; MS (EI) m/z 193, 165, 147, 135, 119, 107, 91,
79, 65 and 51.
3.4.13. Ethyl 3-ethoxy-2-hydroxy propionate (37d). Pale-
yellow oil, IR (NaCl)Z3482 (O–H), 1735 (C]O) cmK1
;
1H NMR (CDCl3) d(ppm)Z4.31 (t, 1H, JZ4.8 Hz, CHOH),
4.27 (dq, 2H, JZ5.0, 7.2 Hz, C(O)OCH2CH3), 3.72 (d, 2H,
JZ3.4 Hz, CH(OH)CH2), 3.57 (dq, 1H, JZ8.9, 7.1 Hz,
CH3CHHO), 3.52 (dq, 1H, JZ8.9, 7.1 Hz, CH3CHHO),
3.16 (brd, 1H, CHOH), 1.31 (t, 3H, JZ7.1 Hz, C(O)OCH2-
CH3) and 1.19 (t, 3H, JZ7.0 Hz, CH3CH2O); 13C NMR
(CDCl3) d(ppm)Z172.6, 71.7, 70.7, 67.0, 61.7, 14.9 and
14.1; MS (EI) m/z 129, 119, 104, 89, 76, 59 and 43; HRMS
found: m/z 162.0885 [M]C. Calcd for C7H14O4: M,
162.0892.
3.4.8. Ethyl anti-3-phenyl-3-ethoxy-2-hydroxy propio-
nate (27d). Pale-yellow oil, IR (NaCl)Z3496 (O–H), 1735
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z7.25–7.35 (m,
5H, C6H5), 4.62 (d, 1H, JZ4.2 Hz, CHOH), 4.08–4.19 (m,
3H), 3.34 (dq, 2H, JZ9.6, 7.0 Hz, CH3CH2O), 2.96 (d, 1H,
JZ7.6 Hz, CHOH), 1.21 (t, 3H, JZ7.1 Hz, CH3CH2O) and
1.19 (t, 3H, JZ7.0 Hz, C(O)OCH2CH3); 13C NMR (CDCl3)
d(ppm)Z171.8, 136.9, 128.1 (2C), 128.0, 127.3 (2C),
127.1, 82.5, 74.3, 65.0, 61.3, 15.1 and 13.9; MS (EI) m/z
193, 165, 147, 135, 119, 107, 91, 79, 65 and 51.
3.4.14. Ethyl 3-n-propyroxy-2-hydroxy propionate
(38d). Pale-yellow oil, IR (NaCl)Z3504 (O–H), 1735
(C]O) cmK1; 1H NMR (CDCl3) d(ppm)Z4.30 (t, 1H, JZ
3.6 Hz, CHOH), 4.26 (dq, 2H, JZ3.9, 7.1 Hz, C(O)OCH2-
CH3), 3.72 (d, 2H, JZ3.1 Hz, CH(OH)CH2), 3.48 (dt, 1H,
JZ9.1, 6.8 Hz, CH2CHHO), 3.40 (dt, 1H, JZ9.1, 6.8 Hz,
CH2CHHO), 3.23 (brs, 1H, CHOH), 1.58 (sextet, 2H, JZ
7.1 Hz, CH3CH2CH2O), 1.31 (t, 3H, JZ7.1 Hz,
C(O)OCH2CH3) and 0.89 (t, 3H, JZ7.1 Hz, CH3CH2CH2-
O); 13C NMR (CDCl3) d(ppm)Z172.6, 73.2, 71.9, 70.7,
61.5, 22.5, 14.1, 10.3 and 10.2; MS (EI) m/z 177 ([MC
H]C), 147 ([MKCH2CH3]C), 133, 119, 104, 89, 73, 61 and
43; HRMS found: m/z 176.1009 [M]C. Calcd for C8H16O4:
M, 176.1049.
3.4.9. Methyl 3-methoxy-2-hydroxy propionate (33d).
Pale-yellow oil, IR (NaCl)Z3430 (O–H), 1737
(C]O) cmK1 1H NMR (CDCl3) d(ppm)Z4.32 (t, 1H,
;
JZ3.2 Hz, CHOH), 3.82 (s, 3H, C(O)CH3), 3.69 (dt, 2H,
JZ4.1, 9.9 Hz, CH(OH)CH2), 3.40 (s, 3H, CH3O) and 3.12
(brs, 1H, CHOH); 13C NMR (CDCl3) d(ppm)Z173.1, 73.9,
70.7, 59.5 and 52.7; MS (EI) m/z 134 (MC), 116 ([MK
H2O]C), 104, 91, 75, 59 and 45; HRMS found: m/z
134.0583 [M]C. Calcd for C5H10O4: M, 134.0579.
3.4.10. Methyl 3-ethoxy-2-hydroxy propionate (34d).
Pale-yellow oil, IR (NaCl)Z3442 (O–H), 1735
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.32 (brs, 1H,

W. Chai et al. / Tetrahedron 61 (2005) 2453–2463
2463
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3.4.15. Ethyl 3-methoxy-2-methyl-2-hydroxy propionate
(39d). Pale-yellow oil, IR (NaCl)Z3504 (O–H), 1735
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.25 (dq, 2H,
7. Moriarty, R. M.; Hu, H.; Gupta, S. C. Tetrahedron Lett. 1981,
22, 1283.
JZ2.3, 7.2 Hz, C(O)OCH2), 3.65 (d, 2H, JZ9.3 Hz,
CH(OH)CH2), 3.46 (brs, 1H, CHOH), 3.37 (s, 3H, CH3O),
1.36 (s, 3H, C(O)CCH3), 1.30 (t, 3H, JZ7.1 Hz,
C(O)OCH2CH3); 13C NMR (CDCl3) d(ppm)Z175.0, 78.4,
74.7, 61.8, 59.5, 21.8 and 14.1; MS (EI) m/z 162 (MC), 144
([MKH2O]C), 130, 117, 99, 89, 71, 57 and 43; HRMS
found: m/z 162.0896 [M]C. Calcd for C7H14O4: M,
162.0892.
8. Moriarty, R. M.; Duncan, M. P.; Prakash, O. J. Chem. Soc.,
Perkin Trans. 1 1987, 1781.
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Tetrahedron Lett. 1999, 40, 6791.
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3.4.16. Ethyl 3-ethoxy-2-methyl-2-hydroxy propionate
(40d). Pale-yellow oil, IR (NaCl)Z3504 (O–H), 1733
1
(C]O) cmK1; H NMR (CDCl3) d(ppm)Z4.18–4.33 (m,
2H, C(O)OCH2CH3), 3.68 (d, 1H, JZ9.1 Hz,
CH(OH)CHH), 3.55 (dq, 1H, JZ9.6, 7.0 Hz, CH3CHHO),
3.49 (dq, 1H, JZ9.6, 7.0 Hz, CH3CHHO), 3.45 (brs, 1H,
CHOH), 3.42 (d, 1H, JZ9.1 Hz, CH(OH)CHH), 1.36 (s,
3H, C(O)CCH3), 1.30 (t, 3H, JZ7.0 Hz, C(O)OCH2CH3)
and 1.16 (t, 3H, JZ7.1 Hz, CH3CH2O), 13C NMR (CDCl3)
d(ppm)Z175.1, 76.2, 75.9, 67.0, 61.7, 21.7, 14.9 and 14.1;
MS (EI) m/z 176 (MC), 158 ([MKH2O]C), 146, 133, 117,
103, 90, 75, 59 and 43; HRMS found: m/z 176.1070 [M]C.
Calcd for C8H16O4: M, 176.1049.
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Acknowledgements
This work was partially supported by the Frontier Project
‘Environmental Changes and Life Adaptation Strategies’
and a Grant-in-Aid for Scientific Research (No. 15550140).
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