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Title: Mechanistic studies of the pathways leading to ethers via coupling of alcohols

The reaction mechanisms for the solid acid-catalyzed dehydrative coupling of methanol and ethanol with isobutanol and 2-pentanol to form ethers were examined by using isotope labelling and chiral inversion experiments. When the reactions were carried out it 110{degrees}C and 1 MPa with {sup 18}O-ethanol and {sup 16}O-isobutanol over the Amberlyst-35 resin catalyst, 95% of the major product ethyl isobutyl ether (EIBE) contained {sup 16}O, while 96% of the minor product ethyl tertiarybutyl ether (ETBE) contained {sup 18}O. Similar results were obtained with methanol and isobutanol over Nafion-H and Amberlyst-35 catalysts, with methyl isobutyl ether (MIBE) and methyl tertiarybutyl ether (MTBE) as the products. These results indicate that EIBE (MIBE) was produced by a surface-catalyzed S{sub N}2 reaction, while the ETBE (MTBE) product arose via a carbenium intermediate. The analogous reaction carried out over Nafion-H and HZSM-5 catalysts with chiral 2-pentanol verified the surface-mediated S{sub N}2 reaction, wherein chiral inversion of the product ether was observed relative to the S- and R-2-pentanol reactants.
Authors:
; ; ;  [1]
  1. Zettlemoyer Center for Surface Studies, Bethlehem, PA (United States)
Publication Date:
OSTI Identifier:
433265
Report Number(s):
CONF-950402--
Journal ID: ACFPAI; ISSN 0569-3772; TRN: 97:000007-0028
Resource Type:
Journal Article
Resource Relation:
Journal Name: Preprints of Papers, American Chemical Society, Division of Fuel Chemistry; Journal Volume: 40; Journal Issue: 1; Conference: 209. American Chemical Society (ACS) national meeting, Anaheim, CA (United States), 2-6 Apr 1995; Other Information: PBD: 1995
Country of Publication:
United States
Language:
English
Subject:
02 PETROLEUM; ALCOHOLS; SYNTHESIS; ETHANOL; CONVERSION; ETHERS; METHANOL; ZEOLITES; CATALYTIC EFFECTS; CATALYSTS; FUEL ADDITIVES; 2-METHYLPROPANOL; PENTANOLS; OXYGEN 18; OXYGEN 16; TRACER TECHNIQUES