Thiols alicyclic

The acidic, basic and neutral flavor components of a YA were examined in the first published study, and 48 compounds were identified (5,7). Three sulfur compounds, i.e., 2-thiophenecarboxylic acid, its 5-methyl derivative and 4-methyl-5(2 -hydroxyethyl)thiazole were mentioned. Later, Golovnya et al. (8) identified 37 sulfur compounds from a simulated meat flavor produced by heating a bakery YA with sugar. They included aliphatic sulfides and thiols, alicyclic sulfur compounds, thiophenes and sulfur-substituted furans. 

Fox feces contain trimethylthiazoline (Fig. 3.1 p. 37), which by itself induces in rats even stronger fear responses than whole feces (Vernet-Mauiy, 1980). Of 12 compoimds from fox feces tested, seven elicited fear responses, confirmed by postmortem corticosterone measurements. Some structure-activity relationships emerged. The thiol group is essential, while theketo group is not molecular size can vary mercaptoketones can be aliphatic or alicyclic the thiol can be secondary or tertiary and the thiol can be alpha or beta to the keto group (Vemet-Maury etal, 1984). 

Usually, 3- and 4-substituted thianes are prepared from the 3- and 4-oxothians by the common techniques applicable to alicyclic chemistry. Reduction affords alcohols which may be etherified or halogenated, while oximation and reduction produces the amino derivatives, which are also accessible via the halo compounds. 2-Alkoxy and 2-alkylthio compounds are made by acid catalyzed addition of alcohols and thiols to 3,4-dihydro-2H-thiopyran (75MI22502) in a reaction analogous to the use of dihydropyran for protection of alcohols as THP ethers. 

Desulfurization. Alicyclic thiol sulfonates, for example l,2-dithiolane-l,l-dioxide (1, prepared by oxidation of the corresponding dimercaptan) are desul-... 

The introduction of alicyclic parts into the poly (thiol ester) chain increases conformational rigidity and, consequently, the melting point. This can be seen from the melting points of poly(hexamethylene... 

From these results, it is evident that a number of aromatic or alicyclic poly (thiol esters) have melting points suitable for making fibers. 

There is now general agreement that Vilsmeier reactions with acetals, ketals, and the corresponding thio derivatives proceed by loss of a molecule of alcohol or thiol to give the reactive unsaturated ether or thioether with cyclic ketals the alcohol remains tethered, and may be chlorinated. The acetals and ketals are often more readily available than the unsaturated ethers, and yields of products are similar. A wide range of aliphatic and alicyclic acetals and ketals has been formylated the reaction can tolerate bulky groups at either end of the double bond, as is shown for compound 64 (Eq. 51). Products are isolated as iminium sails... 

The original studies of simple thiols and sulfides, both aliphatic and alicyclic, indicated the feature of interest to be the first ionization band associated with the nonbonding valence p orbital on S6. As illustrated in Figure 4, the ns band is of narrow profile in both H2S (Ji = 10.48 eV) and CH3SH (It = 9.41 eV) so the IE shift of - 1.07 eV is due to the inductive effect of CH3 in which electron density moves onto the S atom. However in (CH3)2S (Ii = 8.72eV), as well as a further inductive shift, the ns band is subject to broadening due to CH hyperconjugative interaction. With increased alkyl substitution... 

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