8- mercapto-p-menthan-3-one

Kopke X Mosandl A, Stereoisomeric flavor compounds. Part LIV 8-Mercapto-p-menthane-3-one -optically pure stereoisomers and chirospecific analysis, Z Lebensm Unters Forsch 194 372—376, 1992. 

Of the few known terpene compounds that contain heteroatoms such as nitrogen or sulfur, the thiol 8-mercapto-p-menthan-3-one described below has qualitatively important applications as a fragrance and flavor substance. The second thiol, -p-menthene-8-thiol, is described because its odor threshold value is far lower than that of most other fragrance and flavor materials. 

Mercapto-p-menthan-3-one has been identified as a constituent of Buchu leaf oil [6] and is a very useful substance in black currant and tropical flavours. The reaction of pulegone with hydrogen sulfide in an alkaline medium results in 8-mercapto-p-menthan-3-one formation (Scheme 13.6). 

Scheme 13.6 Chemical synthesis of 8-mercapto-p-menthan-3-one from pulegone...

Buchu (+)-trans-8-Mercapto- p-menthan-3-one Black currant flavoirrs... 

CIC Ethyl butyrate contribute to the fruity, estery note linalool, alpha-terpineol, citronellol and damascenone support the floral, fruity ripe character and 1,8-cineol imparts the freshness. 4-methoxy-2-methyl-2-mercapto butane is responsible for typical catty sulphurous black currant note. Extracts of the black currant buds are more green, herbaceous but they also contain the sulphurous CIC. A similar note, 8-mercapto-p-menthan-3-one has been identified in buchu oil and is often used to imitate the catty black currant aspect. 

Owing to their characteristic minty-fruity notes, reminiscent of blackcurrants, buchu leaf oils are well appreciated in the composition of flavourings and fragrances. 8-Mercapto-p-menthan-3-one and its thiolacetate have been described by Sundt et al. [98] and simultaneously by Lamparsky et al. ]99]as impact flavouring compounds of the flavour of cassis. They have so far not been identified in blackcurrant. All four stereoisomers of 8-mercapto-p-menthan-3-one exhibit distinct and characteristic sensory impressions ]100]. 

A. Mosandl, T. Kbpke and W. Bensch. Stereoisomeric Elavour compounds. EXIT Structure elucidation of 8-mercapto-p-menthan-3-one isomers. Tetrahedron Asymm., 4, 651-654 (1993). 

Mercaptoimidazoline. See Ethylene thiourea, 8-Mercapto-p-menthane-3-one. See p-Mentha- s-thiol-3-one... 

Buchu oil Barosma betulina Leaf SD (+)-fimonene, irawf-8-mercapto-p-menthane-3-one and its S-acetate derivative... 

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