A highly selective synthesis of monodisperse oligo(ethylene glycols)

Abstract

Although oligo(ethy1ene glycols) [H[-0CH2CH2In-OH, 1 (n ); cf. Scheme I] have found widespread application as synthons for crown ether-type derivatives,l surfactants,2 ion-conducting materials: and new materials: the published synthetic methods for commercially unavailable or expensive representatives l(n) (n > 4) are hampered by (1) Huezthy, P.; Bradshaw, J. S.; Zbu, C. Y.; Izatt, R. M.; Lifson, S. Le Nest, J. F.; Gandini, A.; Armand, M. Polym. Bull. 1991, 25, 443-460. (b) Bianconi, P. A.; Lin, J.; Strzelecki, A. R. Nature 1991,349,315-317. (5) (a) Bedells, A. D.; Mobbe, R. H.; Booth, C. Makromol. Chem. 1991, 192, 2089-2098 and refs cited therein. (b) Coudert, G.; Mpaesi, M.; Guillaumet, G.; Selve, C. Synth. Commun. 1986, f6,1$&26 and refs cited therein. (c) Nakatauji, Y.; Kameda, N.; Okahara, M. Synthesis 1986, 280-281 and refs cited therein. (d) Bradshaw, J. S.; Reeder, R. A.; Thompson, M. D.; Flanders, E. D.; Carruth, R. L.; Izatt, R. M.; Christensen, J. J. J. Org. Chem. 1976, 41, 134-136. (6) (a) Ouchi, M.; Inoue, Y.; Liu, Y.; Nagamune, S.; Nakamura, S.; Wada, K.; Hakushi, T. Bull. Chem. SOC. Jpn. 1990,63,1260-1262 and refs cited therein. (b) Kyba, E. P.; Helgeson, R. C.; Madan, K.; Gokel, G. W.; Tarnowski, T. L.; Moore, 5. S.; Cram, D. J.

Synthesis and characterization of new phenanthrolinetriether copolymers with rotaxane architecture

“…Tri(ethylene glycol) ditosylate was synthesized according to the method of Keegstra et al [13] with modifications. Tri(ethylene) glycol (45.05 g, 0.3 mol) was dissolved in THF (150 mL) in a 2 L two-necked round bottomed flask.…”

2,2′-Bipyridine Lariat Calixcrowns: A New Class of Encapsulating Ligands Forming Highly Luminescent Eu3+ and Tb3+ Complexes

“…First, 1-O-allyl-glycerol [(dl)-11] was protected on the primary hydroxyl by reaction with trityl chloride and triethyl amine in dichloromethane. [16] The monotrityl monotosyl oligoethylene glycols 9 and 10 were prepared by reaction of trityl chloride in pyridine with a large excess of di-or triethylene glycols [18,19] followed by the reaction of the resulting monotrityl ethers (7 and 8) with tosyl chloride in dichloromethane. The resulting monotrityl monotosyl glycols 9 and 10 were allowed to react with the 1-O-allyl-3-O-trityl glycerol [(dl) -12] in basic conditions (NaH, DMF); the products thus formed were deprotected with HCl (36 %) to give glycols 13 and 14 in high yields (75 and 71 %, respectively).…”

“…hydroxymethyl groups symmetrically located on the second and seventh carbon atom of tetraethylene glycol (18). We synthesized compound 18 by following the reactions reported in Scheme 2.…”

Highly Efficient Synthesis of Monodisperse Poly(ethylene glycols) and Derivatives through Macrocyclization of Oligo(ethylene glycols)

“…[3] However, efficient synthesis of M-PEGs remains a long-standing challenge even after decades of efforts [1,4] owing to the following issues (Scheme 1, chain tripling method was illustrated as an example): 1) Long synthesis, low yield, and tedious purification dramatically deteriorate the synthetic efficacy. 2) No synthesis on M-PEGs above 2500 Da has ever been reported.…”