B. Das et al. / Tetrahedron Letters 48 (2007) 4263–4265
4265
obtained by purification of the crude products
established their structures. In the H NMR spectra of
Acknowledgement
1
b-aryloxyalcohols derived from 2-alkyl epoxides, the
The authors thank the CSIR, New Delhi, for financial
assistance.
CHOH and –CH (OAr) protons resonated at ca d
2
1
4
.3 and 4.0, respectively. On the other hand, in the H
NMR spectra of b-aryloxyalcohols produced from
styrene oxide, the CH(OAr) and –CH OH protons
References and notes
2
appeared at ca. d 5.2 and 3.7, respectively. These values
clearly established the regiochemistry of the b-aryloxy-
alcohols obtained from 2-alkyl epoxides and styrene
oxide. The ring-opening of bicyclic epoxides took place
with anti-selectivity to furnish the products with the
1. (a) Baker, N.; Byrne, N.; Economides, A.; Javeld, T. Chem.
Pharm. Bull. 1995, 1045; (b) Wright, J.; Gregory, T.;
Heffner, T.; MacKenzie, R.; Pugsley, T.; Meulen, S.; Wire,
L. Bioorg. Med. Chem. Lett. 1997, 7, 1377; (c) Kitori, K.;
Furukawa, Y.; Yoshimoto, H.; Otera, J. Tetrahedron 1999,
1
trans-configuration. In the H NMR spectra of the
5
5, 14381.
products, the coupling constants of the ring protons
adjacent to the –OAr and –OH groups provided
evidence for this stereochemical assignment. For exam-
ple, the J values of these two protons for 3u are 9.5,
2
. (a) Chen, J.; Shun, W. Tetrahedron Lett. 1995, 36, 2379; (b)
Palermo, S.; Waykole, L.; Chen, K. M.; Prashad, M.;
Prasad, K.; Repic, O.; Blacklock, T. J. Synth. Commun.
1997, 27, 1757; (c) Kamal, A.; Ahmed, S. K.; Sandbhor, M.;
Khan, M. N. A.; Arifuddin, M. Chem. Lett. 2005, 34,
1142.
9
.0 and 4.0 Hz and 9.2, 9.0 and 4.0 Hz, suggesting the
trans-configuration of the compound.
3
4
. (a) Iranpoor, N.; Firouzabadi, H.; Safavi, A.; Shekarriz, M.
Synth. Commun. 2002, 32, 2287; (b) Surendra, K.; Krish-
naveni, N. S.; Nageswar, Y. V. D.; Rao, K. R. J. Org.
Chem. 2003, 68, 4994; (c) Tamami, B.; Iranpoor, N.;
Rezaei, R. Synth. Commun. 2004, 34, 2789.
. (a) Das, B.; Ramu, R.; Ravikanth, B.; Reddy, K. R.
Tetrahedron Lett. 2006, 47, 779; (b) Das, B.; Thirupathi, P.;
Reddy, V. S.; Rao, Y. K. J. Mol. Catal. A: Chem. 2006,
247, 233; (c) Das, B.; Krishnaiah, M.; Venkateswarlu, K.
Tetrahedron Lett. 2006, 47, 233; (d) Das, B.; Ravikanth, B.;
Thirupathi, P.; Rao, B. V. Tetrahedron Lett. 2006, 47,
Polyethylene glycol (PEG-400) has been used here for
the preparation of b-aryloxy alcohols from epoxides.
6
It is an eco-friendly, biologically acceptable, inexpensive
polymer. However, its applications as a reaction med-
ium in organic syntheses are still limited. In the present
conversion, the role of PEG is possibly to activate the
epoxide ring by hydrogen bonding thus facilitating the
nucleophile attack by the phenoxide ion. The PEG
was recovered from the reaction mixture and was recy-
cled without loss of activity.
5
041.
. (a) Dickerson, T. J.; Reed, N. N.; Janda, K. D. Chem. Rev.
002, 102, 3325; (b) Chandrasekhar, S.; Narasihmulu, Ch.;
Sultana, S. S.; Reddy, N. R. Chem. Commun. 2003, 9, 1716;
c) Kamal, A.; Reddy, D. R.; Rajendar. Tetrahedron Lett.
006, 47, 2261.
5
6
2
The ring-opening of epoxides with phenoxides was also
carried out using diethyl ether, methanol and ethanol in
the absence of any catalyst. However, with the first sol-
vent no conversion occurred under the present experi-
mental conditions, while with the other two solvents
the reaction afforded complex mixtures which were dif-
ficult to purify.
(
2
. General experimental procedure: To the suspension of an
epoxide (1 mmol) in PEG (2 g), the phenoxide (1.1 mmol)
was added and the mixture was stirred at room tempera-
ture. The reaction was monitored by TLC. After comple-
tion, the mixture was poured onto water and extracted with
EtOAc (3 · 10 mL). The extract was concentrated and the
residue was subjected to column chromatography (silica
gel, ethyl acetate–hexane 2:8) to obtain the pure b-
aryloxyalcohol. The PEG was recovered from the water
and recycled without affecting the yields of the products.
In conclusion, we have described a novel and efficient
protocol for conversion of epoxides into b-aryloxyalco-
hols using PEG as the reaction medium at room
temperature.