Prins cyclization of styrenes or acetophenone catalyzed by DBSA in water

Article abstract of DOI:10.1080/00397911.2010.538891

Dodecylbenzenesulfonic acid (DBSA) was proved to be an efficient catalyst for Prins cyclization of styrenes and formaldehyde or acetaldehyde in water. A tandem dehydration/ Prins cyclization reaction using a tertiary alcohol and formaldehyde as substrates proceeded very well by using DBSA as catalyst. Acetophenone, which is less reactive compared with styrene, can also react with formaldehyde when catalyzed by DBSA in water to afford 1,3-dioxan-5- ylphenylmethanone in good yield. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/00397911.2010.538891

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Prins Cyclization of Styrenes or
Acetophenone Catalyzed by DBSA in
Water
Juan Zhang a , Lin Hua b , Feifei Li b , Xuefen Wu a , Shengzhi Tian a
& Jing Yang a
a Henan University of Traditional Chinese Medicine, Zhengzhou,
China
b Institute of Chemistry, Henan Academy of Sciences, Zhengzhou,
China
Accepted author version posted online: 07 Oct 2011.Published
online: 22 Dec 2011.
To cite this article: Juan Zhang , Lin Hua , Feifei Li , Xuefen Wu , Shengzhi Tian & Jing Yang (2012)
Prins Cyclization of Styrenes or Acetophenone Catalyzed by DBSA in Water, Synthetic Communications:
An International Journal for Rapid Communication of Synthetic Organic Chemistry, 42:8, 1234-1242,
DOI: 10.1080/00397911.2010.538891
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Synthetic Communications1, 42: 1234–1242, 2012
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397911.2010.538891
PRINS CYCLIZATION OF STYRENES OR
ACETOPHENONE CATALYZED BY DBSA IN WATER
Juan Zhang,1 Lin Hua,2 Feifei Li,2 Xuefen Wu,1
Shengzhi Tian,1 and Jing Yang1
1Henan University of Traditional Chinese Medicine, Zhengzhou, China
2Institute of Chemistry, Henan Academy of Sciences, Zhengzhou, China
GRAPHICAL ABSTRACT
Abstract Dodecylbenzenesulfonic acid (DBSA) was proved to be an efficient catalyst for
Prins cyclization of styrenes and formaldehyde or acetaldehyde in water. A tandem dehy-
dration/Prins cyclization reaction using a tertiary alcohol and formaldehyde as substrates
proceeded very well by using DBSA as catalyst. Acetophenone, which is less reactive com-
pared with styrene, can also react with formaldehyde when catalyzed by DBSA in water to
afford 1,3-dioxan-5-ylphenylmethanone in good yield.
Keywords DBSA; 1,3-dioxane; organic reactions in water; Prins cyclization
Organic reactions in water are currently of interest in organic synthesis.[1] In addition
to environmental and economical advantages, unique reactivity and selectivity that
are not achieved in organic solvents are often observed in water, and several inter-
esting and useful reactions have been exploited by using water as the solvent.
Although advantages of using water as solvent for organic reactions have been well
documented, owing to the low solubility of most of organic substrates in water,
much effort has been paid to facilitating the interaction of catalyst and substrate.[2]
Among all the catalysts developed for organic reactions, surfactant-combined
catalyst could be one of the most efficient systems. It possesses functions of both
Received September 27, 2010.
Address correspondence to Jing Yang, Henan University of Traditional Chinese Medicine,
Zhengzhou 450008, China. E-mail: candyyjing@163.com
1234

PRINS CYCLIZATION OF STYRENES OR ACETOPHENONE
1235
emulsification reagent and catalyst and consequently is capable of mixing both the
hydrophobic and hydrophilic phases in the reaction system. Kobayashi’s groups first
demonstrated the feasibility for applying a surfactant-combined acid catalyst,
dodecylbenzenesulfonic acid (DBSA), in studies of organic reactions in water[3]
and contributed more than 10 papers in this area.[4] Since then, many other anal-
ogous surfactant-combined systems have been developed for catalysis and organic
synthesis.[5] In view of the high efficiency and green aspect of surfactant-combined
catalyst, it is necessary to utilize them further in organic synthesis.
1,3-Dioxane derivatives are widely used in pharmaceutical synthesis as solvents
or intermediates.[6] Condensation of activated olefins with carbonyls, such as alde-
hydes, known as the Prins reaction, has been considered as one of the most efficient
methods for the synthesis of 1,3-dioxanes.[7] Although there are many reports on the
use of Lewis and Brønsted acids as catalysts for this type of reaction,[8] most of them
include the use of paraformaldehyde as a HCHO source. Furthermore, to facilitate
decomposition of the solid paraformaldehyde, a polar organic solvent, for example,
1,2-dichloroethane, which is volatile and toxic, has to be used. Performing the Prins
reaction in water perfectly fits the requirement of green chemistry, and this idea has
recently been realized using formaldehyde aqueous solution as HCHO source.
However, the catalysts have been plagued by either high cost or poor efficiency.[9]
In this article, we report that DBSA can act as an efficient catalyst for Prins cycliza-
tion of styrenes and formaldehyde in water. Acetophenone, which is less reactive
compared with styrene, can also react with formaldehyde under catalysis of DBSA
in water to afford 1,3-dioxan-5-ylphenylmethanone derivatives in good yields
(Scheme 1). Our report not only offers an inexpensive and efficient catalyst for these
reactions but also describes the use of formaldehyde aqueous solution instead of
paraformaldehyde.
Initially, reaction of styrene and formaldehyde was performed in water using
DBSA and aqueous formaldehyde solution as catalyst and HCHO source. The reac-
tion was carried out at 80 ꢀC without any precautions. As shown in Table 1, 62%
yield was obtained when 5 mol% of catalyst was used. Increase of catalyst amount
results in a significant improvement on the reaction yield, and the yield reached
97% when 12 mol% of DBSA was used (entries 1 to 3). It should be noted that excess
formaldehyde has to be used to get a good reaction yield (entry 4). Extra addition of
Scheme 1. Prins cyclization of styrene and acetophenone with formaldehyde.

1236
J. ZHANG ET AL.
Table 1. DBSA-catalyzed Prins cyclization of styrene and formaldehydea
Entry
X
Temp. (ꢀC)
Time (h)
Yield (%)
1
5
8
80
80
80
80
80
50
80
80
4
4
4
4
4
4
2
4
62
89
97
66
87
44
80
95
2
3
12
12
12
12
12
12
4b
5c
6
7
8d
aStyrene: 1.0 mmol.
bFormaldehyde was used in 2.5 equiv.
c0.5 ml of water was added.
dReaction was conducted on a 10-mmol scale.
water seems detrimental for the model reaction (entry 5). Further investigation
revealed that the reaction was also affected by temperature and reaction time, and
the optimal conditions are 80 ꢀC and 4 h (entries 6 and 7). Under these conditions,
the reaction scale could be increased to 10 mmol without significant effect on the
product yield (entry 8), indicating the good performance of DBSA for this type of
reaction.
Having these results in hand, many other styrenes were then examined in this
system, and the results are listed in Table 2. Styrenes substituted by
electron-donating groups, such as methyl and chloro substituents, in the aromatic
ring give better yields than those substituted by electron-withdrawing groups. The
presence of a methyl group in the a-position of the double bond has an apparent pro-
moting effect on the reactivity of styrene substrates (entries 4 and 5). However, the
methyl group in the b-position lowered the reactivity significantly (entries 6 and 7).
For example, at an elevated temperature, 90 ꢀC, Prins cyclization of b,b-dimethyl-
styrene with formaldehyde proceeded sluggishly in the presence of 20 mol%
of DBSA, and finally the desired product, 2h, was obtained in only 34% of yield
(entry 7). It might result from an effect of steric hindrance of the two methyl groups
in b-position of the double bond. Another styrene-type olefin, b-vinylnaphthalene,
can also be used in a DBSA system, but the yield obtained is inferior to the normal
styrene (entry 8). Not only formaldehyde but also acetaldehyde can be used in
DBSA-catalyzed Prins cyclization of styrenes. For example, in the presence of
20 mol% of DBSA at 90 ꢀC, a-methylstyrene can react smoothly with acetaldehyde,
and the corresponding adduct, 2h, was obtained in 81% yield (Scheme 2). However,
aromatic aldehyde cannot be used in this reaction.
´ ˆ
Gu and Jerome have recently developed a tandem dehydration=Prins cycliza-
tion reaction using silica-supported sulfonic acid with the aid of a hydrophobic ionic
liquid.[10] Although Gu’s system works well in water, because of the high cost of

PRINS CYCLIZATION OF STYRENES OR ACETOPHENONE
1237
Table 2. Substrate scope for styrenes in DBSA-catalyzed Prins cyclizationa
Entry
Styrene
Time (h)
Product
Yield (%)
1
2
4
8
2b
2c
91
90
3
4
5
6
2
3
2d
2e
2f
88
90
87
6
10
10
4
2g
2h
2i
61
34
48
7b
8c
aStyrene: 1.0 mmol, formaldehyde aqueous solution: 4.0 mmol, DBSA: 12 mol%, temperature: 80 ꢀC.
bDBSA: 20 mol% and temperature: 90%.
cTemperature: 50 ꢀC.
ionic liquid and tedious procedure for preparation of the silica catalyst, it would be
interesting if a simple and easily available one can act as an alternative catalyst. We
thus investigated the reaction of tertiary alcohols using DBSA as catalyst in aqueous
formaldehyde solution. As shown in Scheme 3, the tandem dehydration=Prins cycli-
zation reaction proceeded well in water in the presence of 12 mol% of DBSA, and the
corresponding products were obtained in good yields.
It is well known that acetophenone is able to react with formaldehyde to afford
1,3-dioxanes in the presence of acid or metal catalysts.[11] However, because of the
low reactivity of acetophenone derivatives in this type of reaction, few catalysts have
Scheme 2. DBSA-catalyzed Prins cyclization of a-methylstyrene and acetaldehyde.

1238
J. ZHANG ET AL.
Scheme 3. DBSA-catalyzed tandem dehydration=Prins cyclization of tertiary alcohols in water.
been proved to be effective until now. Good activity of DBAS observed in the pre-
viously mentioned reaction encouraged us to examine the reactivity of acetophenone
in aqueous solution of formaldehyde. As shown in Scheme 4, the expected product,
4a, was obtained in 77% yield after 10 h of reaction at 90 ꢀC. This example indicated
that DBSA can be used as an efficient and water-compatible acid catalyst for
formaldehyde-participated cyclization reactions.
In conclusion, DBSA proved to be an efficient catalyst for Prins cyclization of
styrenes and formaldehyde or acetaldehyde in water. A tandem dehydration=Prins
cyclization reaction using a tertiary alcohol and formaldehyde as substrates pro-
ceeded very well using DBSA as catalyst. Acetophenone, which is less reactive com-
pared with styrene, can also react with formaldehyde under catalysis of DBSA in
water to afford 1,3-dioxan-5-ylphenylmethanone derivatives in good yields.
EXPERIMENTAL
1
All chemicals are used as received without any purification. H and 13C NMR
spectra were recorded on a Bruker AV-400 instrument. Chemical shifts are expressed
in parts per million (ppm) relative to Me4Si in CDCl3. Infrared (IR) spectra were
recorded on a Fourier transform (FT)–IR Bruker (VERTEX 70) using KBr tech-
nology. High-resolution mass spectrometer (HRMS) analysis was measured on a
VG ZAB HS Instrument.
Typical Procedure for Prins Cyclization of Styrenes
All the reactions were conducted in a 10-mL U-type flask equipped with mag-
netic stirring. In a typical reaction, formaldehyde (37 wt%, 324.0 mg) was mixed with
styrene (1a, 104.0 mg, 1.00 mmol) and DBSA (39.1 mg, 12 mol%) under air. The
mixture was then heated at 80 ꢀC for 4 h. After the reaction, the mixture was cooled
Scheme 4. DBSA-catalyzed cyclization reaction of acetophenone and formaldehyde in water.

PRINS CYCLIZATION OF STYRENES OR ACETOPHENONE
1239
to room temperature and then extracted with a mixture of ethyl acetate and heptane
(v=v ¼ 1=1, 2 ml ꢁ 3). The obtained organic solutions were concentrated and then
subjected to isolation with preparative thin-layer chromatography (TLC) using a
mixed solution of ethyl acetate and petro ether as eluting solvent (normally, the ratio
of ethyl acetate=petroether is 1=6).
Spectroscopic Data of Products
4-Phenyl-1,3-dioxane (2a).[9(a)] Colorless liquid; 1H NMR (CDCl3) d
1.67–1.71 (m, 1H), 2.03–2.12 (m, 1H), 3.82–3.88 (m, 1H), 4.13–4.20 (m, 1H), 4.62
(d, J ¼ 11.6 Hz, 1H), 4.85–4.90 (m, 1H), 5.19 (d, J ¼ 6.4 Hz, 1H), 7.22–7.30 (m,
1H); 13C NMR (CDCl3) d 33.9, 66.8, 78.8, 94.3, 125.8, 128.0, 128.6, 141.6.
4-(4-Methylphenyl)-1,3-dioxane (2b).[10] Colorless liquid; 1HNMR
(CDCl3) d 1.69 (d, J ¼ 13.6 Hz, 1H), 2.08 (qd, Ja ¼ 9.6 Hz, Jb ¼ 4.8 Hz, 1H), 2.33
(s, 3H), 3.89 (dd, Ja ¼ 13.6 Hz, Jb ¼ 2.0 Hz, 1H), 4.20 (dd, Ja ¼ 12.0 Hz, Jb ¼ 4.8 Hz,
1H), 4.63 (d, J ¼ 11.2 Hz, 1H), 4.90 (d, J ¼ 6.4, 1H), 5.18 (d, J ¼ 6.4 Hz, 1H), 7.21
(m, 4H); 13C NMR (CDCl3) d 21.1, 33.9, 66.9, 78.7, 94.1, 125.6, 129.2, 137.6, 138.5.
4-(4-Tert-butylphenyl)-1,3-dioxane (2c).[9(a)] Colorless liquid; 1H NMR
(CDCl3) d 1.32 (s, 9H), 1.70 (dt, Ja ¼ 13.6 Hz, Jb ¼ 0.8 Hz, 1H), 2.09 (dd,
Ja ¼ 11.8 Hz, Jb ¼ 4.8 Hz, 0.5H), 2.16 (dd, Ja ¼ 11.8 Hz, Jb ¼ 4.8 Hz, 0.5H), 3.86 (td,
Ja ¼ 11.6 Hz, Jb ¼ 2.4 Hz, 1H), 4.21 (dd, Ja ¼ 11.2 Hz, Jb ¼ 4.8 Hz, 1H), 4.61 (dd,
Ja ¼ 11.2 Hz, Jb ¼ 2.4 Hz, 1H), 4.89 (d, J ¼ 6.4 Hz, 1H), 5.21 (d, J ¼ 6.4 Hz, 1H),
7.30 (d, J ¼ 8.4 Hz, 2H), 7.38 (d, J ¼ 8.4 Hz, 2H); 13C NMR (CDCl3) d 31.8, 34.2,
35.1, 67.3, 79.1, 94.6, 125.8, 126.1, 138.8, 151.1.
4-(4-Chlorophenyl)-1,3-dioxane (2d).[8(a)] Colorless liquid; 1H NMR
(CDCl3) d 1.69 (dt, Ja ¼ 13.6 Hz, Jb ¼ 0.8 Hz, 1H), 2.01 (ddd, Ja ¼ 12.8 Hz,
Jb ¼ 4.8 Hz, Jc ¼ 1.6 Hz, 1H), 3.87 (td, Ja ¼ 12.0 Hz, Jb ¼ 2.4 Hz, 1H), 4.20 (dd,
Ja ¼ 11.6 Hz, Jb ¼ 4.8 Hz, 1H), 4.62 (dd, Ja ¼ 11.2 Hz, Jb ¼ 2.4 Hz, 1H), 4.88 (d,
J ¼ 6.4 Hz, 1H), 5.21 (d, J ¼ 6.4 Hz, 1H), 7.24–7.37 (m, 4H); 13C NMR (CDCl3) d
34.2, 67.2, 78.3, 94.6, 127.5, 129.1, 133.8, 140.2.
4-Methyl-4-phenyl-1,3-dioxane (2e).[9(b)] Colorless liquid, 1H NMR
(CDCl3) d1.41 (s, 3H), 2.05–2.29 (m, 2H), 3.64 (td, Ja ¼ 11.2 Hz, Jb ¼ 2.8 Hz, 1H),
3.86–3.93 (m, 1H), 4.66 (d, J ¼ 6.8 Hz, 1H), 4.87 (d, J ¼ 6.4 Hz, 1H), 7.19–7.27 (m,
1H); 7.29–7.33 (m, 4H); 13C NMR (CDCl3) d 31.1, 33.9, 62.8, 74.7, 88.1, 124.9,
126.1, 127.7, 143.1.
4-(Chlorophenyl)-4-methyl-1,3-dioxane (2f).[9(a)] Colorless liquid, 1H
NMR (CDCl3) d 1.38 (s, 3H), 2.02–2.20 (m, 2H), 3.60 (td, Ja ¼ 10.4 Hz, Jb ¼ 3.2 Hz,
1H), 3.83–3.90 (m, 1H), 4.63 (d, J ¼ 6.8 Hz, 1H), 4.83 (d, J ¼ 6.8 Hz, 1H), 7.17–7.29
(m, 4H); 13C NMR (CDCl3) d 30.7, 33.9, 62.4, 74.2, 88.2, 126.1, 127.8, 131.8, 141.9.
5-Methyl-4-phenyl-1,3-dioxane (2g).[9(a)] (Colorless oil) cis=trans ¼ 48:52.
1
1
cis-Isomer identified by H NMR; H NMR d 0.87 (d, J ¼ 7.3 Hz, 3H), 1.82 (m,
1H), 3.93 (d, J ¼ 11.2 Hz, 1H), 4.01 (dd, J ¼ 11.0 Hz, J ¼ 2.3 Hz, 1H), 4.84 (d,
J ¼ 2.3 Hz,1H), 4.86 (d, J ¼ 6.4 Hz, 1H), 5.21 (d, J ¼ 6.0 Hz, 1H), 7.18–7.37 (m,
5H); trans-isomer identified by 1H NMR; 1H NMR d 0.56 (d, J ¼ 6.4 Hz, 3H),

1240
J. ZHANG ET AL.
2.02–2.15 (m, 1H), 3.38 (t, J ¼ 11.4 Hz, 1H), 4.04 (d, J ¼ 10.6, 1H), 4.08 (d,
J ¼ 10.1 Hz, 1H), 4.80 (d, J ¼ 6.4 Hz, 1H), 5.17 (d, J ¼ 6.4 Hz, 1H), 7.18–7.37 (m,
5H); 13C NMR d 11.1, 12.5, 34.8, 36.4, 73.0, 73.0, 80.5, 86.2, 94.1, 94.5, 125.1,
127.0, 127.3, 128.1, 128.2, 128.3, 139.4, 140.4.
5,5-Dimethyl-4-phenyl-1,3-dioxane (2h).[12] Colorless liquid; 1H NMR
(CDCl3) d 1.16 (s, 3H), 1.26 (s, 3H), 3.02 (dd, J ¼ 11.2 Hz, J ¼ 4.2 Hz, 1H), 3.95
(dd, J ¼ 11.2, J ¼ 4.8 Hz, 1H), 4.10 (t, J ¼ 11.2 Hz, 1H), 4.94 (d, J ¼ 6.8 Hz, 1H),
5.05 (d, J ¼ 6.8 Hz, 1H), 7.07–7.19 (m, 2H), 7.19–7.31 (m, 3H); 13C NMR (CDCl3)
d 19.1, 28.7, 51.1, 66.5, 75.3, 88.1, 127.0, 128.1, 129.3, 138.8.
1
4-(2-Naphthyl)-1,3-dioxane (2i).[9(a)] Colorless liquid, H NMR (CDCl3) d
1.81 (d, J ¼ 13.6 Hz, 1H), 2.10–2.25 (m, 1H), 3.91 (t, J ¼ 11.6 Hz, 1H), 4.21 (d,
J ¼ 7.6 Hz, 1H), 4.81 (d, J ¼ 11.6 Hz, 1H), 4.97 (dd, Ja ¼ 6.4 Hz, Jb ¼ 2.3 Hz, 1H),
5.29 (d, J ¼ 6.4 Hz, 1H), 7.41–7.56 (m, 3H), 7.78–7.96 (m, 4H); 13C NMR (CDCl3)
d 34.1, 67.0, 78.8, 94.2, 123.9, 124.5, 125.9, 126.1, 127.7, 128.3, 128.2, 133.0, 133.4,
138.6.
(2RS,4SR,6RS)-2,4,6-Trimethyl-4-phenyl-1,3-dioxane.[13] 1H NMR (CDCl3):
d 1.22 (d, J ¼ 6.4 Hz, 3H), 1.34 (d, J ¼ 4.8 Hz, 3H), 1.40 (s, 3H), 1.67 (dd, J ¼ 11.6 Hz,
J ¼ 14.0 Hz, 1H), 2.32 (dd, J ¼ 2.0 Hz, J ¼ 13.6 Hz, 1H), 3.66 (ddq, Ja ¼ 2.0 Hz,
Jb ¼ 6.4 Hz, Jc ¼ 11.6 Hz, 1H), 4.70 (q, J ¼ 5.2 Hz, 1H), 7.19–7.27 (m, 1H),
7.31–7.39 (m, 4H); 13C NMR (CDCl3): d 21.2, 21.6, 34.4, 41.2, 68.9, 76.5, 93.5,
125.8, 126.8, 128.7, 144.6.
(2RS,4RS,6RS)-2,4,6-Trimethyl-4-phenyl-1,3-dioxane.[13] 1H NMR (CDCl3):
d 1.23 (d, J ¼ 6.4 Hz, 3H), 1.42 (d, J ¼ 5.2 Hz, 3H), 1.58 (s, 3H), 1.61 (dd,
Ja ¼ 11.6 Hz, Jb ¼ 13.2 Hz, 1H), 1.79 (dd, Ja ¼ 2.4 Hz, Jb ¼ 13.2 Hz, 1H), 4.00 (ddq,
Ja ¼ 2.4 Hz, Jb ¼ 6.4 Hz, Jc ¼ 11.6 Hz, 1H), 5.18 (q, J ¼ 5.2 Hz, 1H), 7.18–7.26 (m,
1H), 7.28–7.38 (m, 2H), 7.42–7.46 (m, 2H). 13C NMR (CDCl3): d 21.7, 21.9, 23.3,
43.6, 68.5, 74.4, 92.1, 123.9, 126.8, 128.2, 148.8.
(2RS,4SR,6SR)-2,4,6-Trimethyl-4-phenyl-1,3-dioxane.[13] 1H NMR (CDCl3):
d 1.16 (d, J ¼ 6.4 Hz, 3H), 1.39 (d, J ¼ 5.2 Hz, 3H), 1.49 (s, 3H), 2.16 (dd, [B-part of
an AB spectrum]), Ja ¼ 8.0 Hz, Jb ¼ 13.6 Hz, 1H), 2.20 (dd [A-part of an AB Spec-
trum]), Ja ¼ 5.2 Hz, Jb ¼ 14.0 Hz, 1H), 4.27 (ddq, Ja ¼ 5.2 Hz, Jb ¼ 8.0 Hz,
Jc ¼ 14.0 Hz, 1H), 5.00 (q, J ¼ 5 Hz, 1H), 7.22–7.30 (m, 1H), 7.33–7.39 (m, 4H).
13C NMR (CDCl3): d 21.4, 21.9, 29.2, 42.3, 68.7, 75.4, 92.9, 124.6, 126.9, 128.4,
148.1.
1,3-Dioxan-5-ylphenylmethanone (4a).[11(a)] 1H NMR (CDCl3): d 4.11 (m,
3H), 4.32 (d, J ¼ 7.8 Hz, 2H), 4.74 (d, J ¼ 7.8 Hz, 1H), 7.45–7.53 (m, 3H), 5.08 (d,
J ¼ 6.8 Hz, 1H), 8.01 (d, J ¼ 7.2 Hz, 2H); 13C NMR (CDCl3) d 43.2, 69.1, 93.0,
127.2, 128.1, 133.4, 135.2, 196.2.
ACKNOWLEDGMENT
We gratefully acknowledge the financial support from the Doctoral Research
Fund of Henan University of Traditional Chinese Medicine.

PRINS CYCLIZATION OF STYRENES OR ACETOPHENONE
1241
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5. Selected examples: (a) Karam, A.; Villandier, N.; Delample, M.; Koerkamp, C. K.;
Douliez, J.-P.; Granet, R.; Krausz, P.; Barrault, J.; Jerome, F. Rational design of
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solution of sodium dodecyl sulfate (SDS) catalyzes facile Michael addition of amines
and thiols to a,b-unsaturated ketones in water under neutral conditions. Adv. Synth.
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for the self-aldol condensation of aldehydes using lysine. Green Chem. 2010, 12, 384–386.
6. Pastor, I. M.; Yus, M. The Prins reaction: Advances and applications. Curr. Org. Chem.
2007, 11, 925–957.
7. Arundale, E.; Mikeska, L. A. The olefin-aldehyde condensation: The Prins reaction,
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8. Some recent examples: (a) Yadav, J. S.; Reddy, B. V. S.; Bhaishya, G. InBr3-[bmim]PF6:
A novel and recyclable catalytic system for the synthesis of 1,3-dioxane derivatives. Green
Chem. 2003, 5, 264–266; (b) Li, G.; Gu, Y.; Ding, Y.; Zhang, H.; Wang, J.; Gao, Q.; Yan,
L.; Suo, J. Wells–Dawson-type molybdovanadophosphoric heteropoly acids–catalyzed
Prins cyclization of alkenes with paraformaldehyde under mild conditions—a facile and
efficient method to 1,3-dioxane derivatives. J. Mol. Catal. A: Chem. 2004, 218, 147–
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by 2,6-di-tert-butylphenoxy(difluoro)borane. Synthesis 2002, 2521–2526; (d) Yadav, J. S.;
Reddy, B. V. S.; Gopal, A. V. H.; Kumar, G. G. K. S. N.; Madavi, C.; Kunwar, A. C.
Iodine as a mild and versatile reagent for the synthesis of 1,3-dioxane derivatives via
the Prins reaction. Tetrahedron Lett. 2008, 49, 4420–4423; (e) Reddy, S. S.; Raju, B. D.;
Kumar, V. S.; Padmasri, A. H.; Narayanan, S.; Rao, K. S. R. Sulfonic acid functionalized
mesoporous SBA-15 for selective synthesis of 4-phenyl-1,3-dioxane. Catal. Commun. 2007,
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as efficient and reusable catalysts for organic reactions in water. Chem. Lett. 2006, 35,
1176–1177; (b) Du, Y.; Tian, F. Efficient synthesis of 1,3-dioxanes catalyzed by trifluoro-
methanesulfonic acid using formalin as formaldehyde source. Catal. Commun. 2007, 8,
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sulfonic acid catalysts in water by coating of ionic liquid. Org. Lett. 2007, 9, 3145–3148.
11. (a) Polshettiwar, V.; Varma, R. S. Tandem bis-aldol reaction of ketones: A facile one-pot
synthesis of 1,3-dioxanes in aqueous medium. J. Org. Chem. 2007, 72, 7420–7422; (b)
Gorrichon, J. P.; Gaset, A.; Delmas, M. A one-step synthesis of 1,3-dioxanes from
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