Thiolane, from thiophene

The "aromatic hydrocarbon" fractions of the laminite sediments from the Nordlinger Ries mainly contain OSC (thiophenes, thiolanes and unidentified... 

Saturated and unsaturated hydrocarbons (Figure 6C) of the pyrolysate are largely dominated by straight-chain hydrocarbons ranging from C14 to C32. There is a drastic drop of concentration of saturated and unsaturated hydrocarbons after the C30 monoenes elutes. The C28, C29, C30 olefins are dominant with their diolefinic counterparts. The FPD trace of the "intermediate" fraction of the pyrolysate (Figure 6D) is dominated by a C30 n-alkylthiophene and by a C30 n-alkylthiolane-thiol tentatively identified from mass spectra. The n-alkylthiophenes dominate throughout the fraction with a distribution ranging from C13 to C32. The C28-C30 are the most prominent thiophenes. The presumed C28-C30 thiolane-thiols show the same distribution as the C28-C30 thiophenes. 

Apart from phytanyl moieties bound by a (poly)sulfide linkage to the macromolecular matrix such phytanyl moieties also occur with an additional intramolecular sulfide linkage. A mass chromatogram of m/z 101 of the 358°C pyrolysate (Figure lib) shows the presence of a C 2q isoprenoid thiolane and its monounsaturated counterparts which are major pyrolysis products. C isoprenoid thiophenes also occur in the pyrolysates but are less abundant. 

In Mesozoic samples, mostly Cretaceous and Jurassic black shales, the abundance and variance of OSC is generally low. A few samples of Jurassic age show a distribution pattern of C20 isoprenoid thiophenes which may indicate increased salinity during deposition. A C20 isoprenoid thiolane is the most abundant compound in black shales from the Falkland Plateau, whereas at other locations the C35 thienylhopane dominates. In one case two C33 mid-chain 2,5-dialkylthiophenes were identified. 

The occurrence of a C20 isoprenoid thiolane, 3-methyl-2-(3,7,11-trimethyldodecyl)thiolane (4), is more restricted (Table II), but it is the most important compound of the "aromatic hydrocarbon" fraction of several Mesozoic black shales from the Falkland Plateau (e.g., late Jurassic sample El 1381 from Site 511 Figure 2). In these samples, additional isoprenoid thiolanes with a base peak at m/z 115 occur in great abundance. Thiolanes have tentatively been suggested as intermediates in the formation of the corresponding thiophenes (24). This is in contradiction to the observation of abundant isoprenoid thiolanes in samples which have experienced more thermal stress and thus are... 

In a Cretaceous slump clast from Site 547 off Morocco (E12743), recovered in the Eocene section, two coeluting C33 mid-chain thiophenes (11 m/z 490(55%), 433(15%), 419(18%), 181(92%), 167(73%), 111(100%)) were detected. Similarly high abundances of C33 mid-chain thiophenes and thiolanes were observed in a sample from the Nordlinger Ries (27) and in the Jurf ed Darawish oil shale (28). 

Sulfur Compounds of Beef Flavor. Methional, which results from the degradation of methionine, is an important contributor to flavor in meat. Thiolanes, formed during the cooking of beef, have peculiar oniony flavors that also augment the quality of the meaty flavor. Thiophenes and thiofurans are also important to meaty flavors. Sulfides, such as methyl sulfide, are oxidized to methyl sulfoxide and methyl sulfone. Condensation reactions of Maillard browning products also result in thiazoles such as benzothiazole, an important component of meat flavor. 

Hitchcock AP, Beaulieu S, Steel T, Stohr J, Sette F (1984) Carbon -Shell electron energy loss spectra of 1- and 2-butenes, trans-l-3-butadiene, and perfluoro-2-butene. Carbon-carbon bond lengths from continuum shape resonances. J Chem Phys 80 3927-3935 Hitchcock AP, Horseley JA, Stohr J (1986a) Inner-shell excitation of thiophene and thiolane Gas, solid, and monolayer states. J Chem Phys 85 4835-4848... 

It has already been noted that sulfur is found in association with nitrogen in the form of the thiazole ring (e.g., as in thiamine, which is shown in Figure 3.4). Few heterocycles are known in nature where sulfur is the sole heteroatom in the ring. Examples are the thiophene derivatives 3.63, isolated from the roots of the Tagetes plant and found to have nematocidal properties, and 3.64 from the marigold plant. The vitamin biotin, whose stmcture is shown in section 3.2.4, has a reduced thiophene (a thiolane) group. 

Various thiolans have been prepared by ionic hydrogenation of thiophens with EtjSiH in the presence of acids. Addition of singlet oxygen to alkyl-substituted thiophens, followed by reduction with di-imine, gave the bicyclic compounds (42) these are examples of the hardly known thia-ozonides. 9-Thia-noradamantane (43) has been synthesized from cyclo-octa-2,7-dienone by a reaction sequence involving a transannular C—H carbene insertion. A bicyclic product (44) has been obtained by the reaction of (—)-carvone with... 

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