7 Reaction Products of
α—Dicarbonyl C o m p o u n d s ,
Aldehydes, H y d r o g e n Sulfide, a n d A m m o n i a HENK J. TAKKEN, LEENDERT M. VAN DER LINDE, PIETER J. DE VALOIS, HANS M. VAN DORT, and MANS BOELENS
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Naarden International Research Department, P.O. Box 2, Naarden-Bussum, The Netherlands
Sulfur compounds have been found in many aromas as well as in several essential o i l s . Although the concentration of these com pounds i s often very low the contribution to the overall flavor can be important due to their odor strength. As a consequence of the low concentration and in some cases the lack of stability the analysis can be extremely difficult. Therefore much attention is paid to the investigation of model systems in which only a few compounds are present which are considered to be precursors of flavor components. An extensive survey of sulfur compounds detected in model systems has been given by Schutte in his review on precursors of sulfur containing flavor compounds (1). Reaction products of aldehydes and hydrogensulfide
Our approach was to investigate the compounds formed by reaction of important flavor components with hydrogensulfide, ammonia and thiols. We f i r s t investigated the reaction products of aldehydes and hydrogensulfide. At atmospheric pressure, mainly cyclic trimers like dioxathianes, oxadithianes and trithianes were formed. However, in a closed glass vessel with excess of hydrogensulfide the reaction mixture consisted mainly of 1,1alkanedithiols and bis-(1-mercaptoalkyl)sulfides ( 2 ) . Although these compounds have not been found in aromas they can be inter mediates for a number of important flavor compounds. The follow ing reactions with bis-(mercaptoalkyl)sulfides have been observed (figure 1): - under oxydative circumstances dialkyltrithiolanes are readily formed - under the influence of acids a complete conversion into trial kyltrithianes does occur - at elevated temperatures isomerisation into trisulfides occurs, which compounds disproportionate into d i - and tetrasulfides - with ammonia dithiazines are formed. 114
Charalambous and Katz; Phenolic, Sulfur, and Nitrogen Compounds in Food Flavors ACS Symposium Series; American Chemical Society: Washington, DC, 1976.
7.
TAKKEN ET AL.
a-Dicarbonyl Compounds, Aldehydes, H S, t
and NH
S
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R e a c t i o n products o f o< -dicarbonylcompounds, aldehydes, hydrogens u l f ide and ammonia We now wish t o r e p o r t on our r e s u l t s o f the a n a l y s i s o f r e a c t i o n mixtures obtained from o< -dicarbonylcompounds, aldehydes, h y d r o g e n s u l f i d e and ammonia. The f o l l o w i n g combinations of ^
