Efficient Synthesis of Spacer-linked Dimers of N-Acetyllactosamine Using Microvawe-assisted Pyridinium Triflate-promoted Glycosylations with Oxazoline Donors

Halasayam Mohan; Emiliano Gemma; Katinka Ruda; Stefan Oscarson

doi:10.1055/s-2003-40340

LETTER

Efficient Synthesis of Spacer-linked Dimers of N-Acetyllactosamine Using Microvawe-assisted Pyridinium Triflate-promoted Glycosylations with Oxazoline Donors

Halasayam Mohan, Emiliano Gemma, Katinka Ruda, Stefan Oscarson*
Department of Organic Chemistry, Arrhenius Laboratory, Floor 6, Stockholm University, 106 91 Stockholm, Sweden
Fax: +46(8)154908; e-Mail: s.oscarson@organ.su.se;

Abstract

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Abstract

Application of pyridinum triflate as promoter combined with microwave heating afforded an easy and efficient synthesis of spacer-linked dimers of LacNAc from the corresponding oxazoline donor. As compared to the promoter pyridinium p-toluenesulfonate the triflate salt increased the yield of dimers with more than 30%, whereas microwave heating improved the yields with a further 15%.

Key words

glycoside - glycosylations - oligosaccharides

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References

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General Procedure for the Synthesis of Dimers Using Microwave Heating: Oxazoline 1 (0.22 mmol), pyridinium triflate (0.22 mmol) and the diol (0.1 mmol) were dissolved in (CH₂Cl)₂ (1 mL) and heated in a sealed vessel in a Smithsynthesizer, a single mode microwave cavity from Personal Chemistry, with a set cut-off temperature of 80 °C for 20 min. Purification directly on a silica gel column (EtOAc/MeOH) gave products 7-10 (62-71%).