S-Trithianes

Reaction of the anion derived from the tosyl imide of l,3,S-trithiane with alkyl iodides gives a mixture of the mono- and di- alkylated products, in which anti stereochemistry predominates. The analogous 1,3-dithiane derivative is only monoalkylated <96JCS(P1)313>. 

The gas inlet tube must be sufficiently long to allow the chlorine to enter near the bottom of the flask, and sufficiently coarse to prevent the pores from becoming clogged by the suspended s-trithiane. A 6-mm. glass tube with a slightly constricted orifice has been found to be equally satisfactory. 

A. Chloromethanesulfonyl chloride. A slurry of 210 g. (1.52 moles) of s-trithiane (Note 1) in a mixture of 1 1. of glacial acetic acid and 210 ml. of water is prepared in a 2-1., three-necked, round-bottomed flask equipped with an efficient mechanical stirrer, a thermometer, a coarsely fritted gas inlet tube (Note 2), and an exit tube by which excess fumes are carried to the rear of the hood. The flask is immersed in an ice bath, and the stirrer is started. A stream of chlorine is introduced at such a rate (Note 3) that the temperature of the mixture is maintained between 40° and 50° by the mildly exothermic reaction. After 1-2 hours a yellow solution results. To this solution is added 300 ml. of water, at which point the temperature rises to ca. 60°. 

Thioacetone was first made in 1889 by Baumann and Fromm (31). They obtained it by reaction of hydrogen sulfide with acetone in the presence of an acidic catalyst. It was a minor product detected by its very disagreeable odor. The major product was hexamethyl-s-trithiane. In more recent work (32, 33) pyrolysis of this intermediate has been developed into a preferred route to thioacetone. 

The reaction of acetone and hydrogen sulfide gives, in addition to hexamethyl-s-trithiane, small amounts of two isomeric impurities, 2,3,5,5,6,6-hexamethyl-1,2,4-trithiane and 4-mercapto-2,2,4,6,6-pentamethyl-l,3-dithiane (32). 

As has been mentioned earlier, thioacetone polymerizes adventitiously even at very low temperatures. The product is a white powder of very high crystallinity. Bailey and Chu (34) state that pure thioacetone gives only polymer, but others always have obtained hexamethyl-s-trithiane in addition to polythioacetone. The... 

A number of higher thioketones have teen prepared by pyrolysis of hexa-substituted trithianes (40, 41). These trithianes were made by methods already discussed for synthesis of hexamethyl-s-trithiane. Those investigated include compounds of the structure... 

Trithiane, sym- S-Trithiane 1,3,5-Trithiane (291-21-4), 65, 90 Triton B Ammonium, benzyltrimethyl-, hydroxide Benzenemethanaminium, N.N.N-trimethyl-, hydroxide (100-85-6), 68, 56 Triton X-100 Glycols, polyethylene, mono[p-(1,1,3,3,-tetramethylbutyl)-phenyl]ether Poly(oxy-1,2-ethanediyl), a-(4-(1,1,3,3-tetramethylbutyl)-phenyl]-ci)-hydroxy- (9002-93-1), 68, 56... 

Aldehyde synthesis. The synthesis of n-pentadecanal from s-trithiane and I -bromo-tctradccane (3, 329) has been published. Purification is accomplished by extraction of 30 g. of commercial s-trithiane with 300 ml. of toluene. 

Saturated heterocyclic rings containing oxygen, nitrogen, or sulfur atoms also exist preferentially in stable, chair conformations resembling that of cyclohexane. Physical measurements, such as those of electron diffraction and dipole moments, have shown this conformation for p-dioxane, -s-trioxane, ° paraldehyde, s-trithiane, and 2,4,6-trimethyl-s-tri-... 

ALDEHYDES 9-Borabicyclo[3.3.1]-nonane. Diazoacetaldehyde. Diethyl-allylthiome thylphosphonate, Diethyl phenyl orthoformate Dithiane. Lith-ium-Alkylamine. Lithium diisopropyl-amide. Sodium tetracarbonylferrate-(TI). 1,1,3,3-Tetramethylbutylisonitrile. 2,4,4,6-Tetramethyl-5,6-dihydro-l, 3-(4H)-oxazine. Triethylsilane. s-Trithiane. 

Purification. Commercial s-trithiane is purified by extraction from a Soxhlet using 300 ml. of toluene for 39 g. of trithiane, followed by recrystallization from the same solvent.1... 

C—C Bond formation. s-Trithiane has been used very much like 1,3-dithiane (2, 182-187) in organic synthesis 2-3 hojvever, the carbanion derived from this reagent tends to undergo carbenoid decomposition. Metalated trithiane reacts readily with primary halides to give 2-alkyl-s-trithianes convertible into aldehydes, as shown for a preparation of n-pentadecanal 1... 

Bost and Constable399 give details for the preparation of trithioformaldehyde (s-trithiane). 

Trithioacetaldehyde (trans-2,4,6-trimethyl-s-trithiane)40 0 is formed when 1 part of acetaldehyde is mixed with 3 parts of ethanol saturated with hydrogen chloride and the mixture is saturated with hydrogen sulfide after recrystallization from alcohol it melts at 125-126°. 

Oxidative desulfurization of thioketals and s-trithianes. Thioketals are converted into the corresponding ketones by treatment with iodine and pyridine N-oxide in DMSO (steam bath, 1 hr.). In the three cases reported, yields were about 80%. Under similar conditions, s-trithianes are converted into aldehydes. The reaction in the latter case may involve the sequence illustrated ... 

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