Ethers sulfur analogs

Sulfides (RSR ) are the sulfur analogs of ethers Just as m the preceding chapter where we saw that the properties of thiols (RSH) are different from those of alcohols we will explore differences between sulfides and ethers m this chapter... 

Sulfides are sulfur analogs of ethers they contain the C—S—C func tional group They are named as al/cylthw derivatives of alkanes m sub stitutive lUPAC nomenclature The functional class lUPAC names of sul tides are derived m the same manner as those of ethers but the concluding word is sulfide... 

Sulfide (Section 16 1) A compound of the type RSR Sulfides are the sulfur analogs of ethers... 

Thiols (R—S—H) and sulfides (R—S—R ) are sulfur analogs of alcohols and ethers, respectively. Both functional groups are found in various biomolecules, although not as commonly as their oxygen-containing relatives. 

Sulfides are the sulfur analogs of ethers just as thiols are the sulfur analogs of alcohols. Sulfides are named by following the same rules used for ethers, with sulfide used in place of ether for simple compounds and alkylthio used in place of alkoxy for more complex substances. 

Thiols, the sulfur analogs of alcohols, are usually prepared by Sjv 2 reaction of an alkyl halide with thiourea. Mild oxidation of a thiol yields a disulfide, and mild reduction of a disulfide gives back the thiol. Sulfides, the sulfur analogs of ethers, are prepared by an Sk2 reaction between a thiolate anion and a primary or secondary alkyl halide. Sulfides are much more nucleophilic than ethers and can be oxidized to sulfoxides and to sulfones. Sulfides can also be alkylated by reaction with a primary alkyl halide to yield sulfonium ions. 

Yu, Q.S. Lu, B.Y (1994) Total Synthesis of Racemic Physostigmine, Physovenine and its Sulfur Analog by the Oxindole-5-O-tetrahydropyranyl Ether Route. Heterocycles, 39, 519-525. 

Sulfur analogs, 2-tetrahydrofuranyl and 2-tetrahydropyranyl thioethers, were reduced by alone to alkyl 4- or alkyl 5-hydroxyalkyl thioethers resulting from the preferential reductive cleavage of the carbon-oxygen (rather than the carbon-sulfur) bond. Thus refluxing for 2 hours with alane in ether converted 2-alkylthiotetrahydrofurans to alkyl 4-hydroxybutyl thioethers in 63-72% yields, and 2-alkylthiotetrahydropyrans to alkyl 5-hydroxypentyl thioethers in 58-82% yields [794]. 

Cyclic sulfur-containing ethers are mainly represented by thio-crowns poly-thioethers [11,569,590,591]. Typical representatives of this group of compounds are 315 (a sulfur analogous to cyclame), 316 (a sulfur analogous to 18-crown-6), and 37 (an interesting variety of metacyclofane) [568] ... 

Sulfur occurs directly beneath oxygen in the periodic table, and, like oxygen, it often exhibits a valence of two. Therefore, sulfur analogs of alcohols and ethers are often encountered. However, because sulfur is in the third period of the periodic table, it can also have a higher valence. Structures with four or six bonds to a sulfur are common. In organic chemistry the most important of these expanded valence compounds have the sulfur bonded to one or two extra oxygens. 

Sulfides (sulfur analogs of ethers) are named by the same system as ethers, with sulfide replacing ether. 

Thio a, R-SH, are sulfur analogs of atcohois, and sulfides, RSR , are si fur analogs of ethers. Thiols am namc by the same system used tor aln-hois, with the suflix -thiol used in place ofThe -SH group itself is referred to as a raerrapto roup. 

The red shift of the HCl stretch, listed in the last row of Table 3.28, is considerably larger than in H O HCl. Nonetheless, this shift of 170 cm is only about half of the experimental quantity of 316 cm. The same trends are observed in. solid matrix. When the proton acceptor in the H20---HC1 complex is changed to dimethyl (or diethyl) ether, the red shift of the HCl stretch increases by several hundred cm Similarly increased red shifts vv hen the base is alkylated are noted for HF and HBr as proton donors. The sulfur analogs, namely, H2S, Mc2S, and 128, obey similar patterns when paired with HF, HCl, and HBr". ... 

Mercaptans and alkyl sulfides are the sulfur analogs of alcohols and ethers, respectively. They can be characterized by their extremely unpleasant odor. These compounds play an important role in biological systems as well as in the application of chemistry to everyday life. Some of the alkyl sulfides are found in many plant and animal oils, and are minor components of petroleum distillates, shale oil, and coal tar. 

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