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A straightforward synthesis of 5‐ethyl‐3‐hydroxy‐4‐methyl‐2(5 H )‐furanone
Author(s) -
Tian HongYu,
Zhang Hao,
Sun Baoguo
Publication year - 2009
Publication title -
flavour and fragrance journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 70
eISSN - 1099-1026
pISSN - 0882-5734
DOI - 10.1002/ffj.1935
Subject(s) - chemistry , yield (engineering) , condensation , base (topology) , oxalate , medicinal chemistry , organic chemistry , condensation reaction , catalysis , mathematical analysis , physics , materials science , mathematics , metallurgy , thermodynamics
5‐Ethyl‐3‐hydroxy‐4‐methyl‐2(5 H )‐furanone has a sweet, maple, caramel odour and is an important flavour compound. It was synthesized starting from diethyl oxalate through the Grignard reaction and condensation. The effects of bases on the condensation of the intermediate, ethyl 2‐oxobutanoate, with propanal were investigated. The self‐condensation predominated when a weaker base, such as K 2 CO 3 , was used, while the yield of the desired product increased with the increasing basicity of the bases used. The self‐condensation could be suppressed completely in the presence of a stronger base, LDA or t‐ BuOK, and 5‐ethyl‐3‐hydroxy‐4‐methyl‐2(5 H )‐furanone was produced in about 90% separated yield in the presence of 3 eq of t‐ BuOK. Copyright © 2009 John Wiley & Sons, Ltd.