Please use this identifier to cite or link to this item:
http://hdl.handle.net/10125/32152
Oligomerization Products from Thiamin in Methanol
File | Size | Format | ||
---|---|---|---|---|
chemistry008.PDF | 7.29 MB | Adobe PDF | View/Open |
Item Summary
Title: | Oligomerization Products from Thiamin in Methanol |
Authors: | Nishida, Clinton |
Contributors: | Chemistry (department) |
Date Issued: | 15 Jan 2014 |
Publisher: | University of Hawaii at Manoa |
Abstract: | In 1974, Shimahara, et al. [1 ] discovered that thiamin (vitamin B1 ) monochloride decomposes in alcohol solution, a reaction which cannot be accounted for solely on the basis of the known instability of thiamin in alkaline solution [2]. Of methanol, ethanol, and propanol, reaction in methanol led to the fastest decomposition rate. Reaction temperature, pH of the solution, and thiamin concentration affected the rate of reaction. For all alcohols, one of the products was determined by IR and NMR spectroscopy to be 5-(2-hydroxyethyl)-4-methyl-thiazole, the thiazole moiety of thiamin. The other product was a crystalline compound designated compound (X), or compound (X') if converted to the nitrate using silver nitrate. Initially believed to be the pentamer nitrate, penta-methi(1 ,4-dihydro-4-imino- 2-methyl-pyrimidinylen-1 ,5-amer nitrate (Fig. 1 a), based on NMR and mass spectral data, compound (X') has since been determined, via single crystal x-ray diffraction, to be the cyclic hexamer (Fig. 1 b, 2) by the Cramer group [4]. The cyclic tetramer has since been isolated and characterized as well (Fig. 1b) [5]. |
Pages/Duration: | ix, 92 pages |
URI: | http://hdl.handle.net/10125/32152 |
Rights: | All UHM Honors Projects are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner. |
Appears in Collections: |
Honors Projects for Chemistry |
Please email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.
Items in ScholarSpace are protected by copyright, with all rights reserved, unless otherwise indicated.