First Synthesis and Reactivities of Isolable Dithiiranes and Their 1-Oxides

Abstract

The reaction of the 6-exo-oxide of 2,2,4,4-tetramethyl-1,5-diphenyl-6,7-dithiabicyclo[3.1.1]heptane (2) with 2KHSO5·KHSO4·K2SO4 gave the first isolable dithiirane oxide, (1RS, 3SR)-3-phenyl-3-(1,1,3,3-tetramethyl-4-oxo-4-phenylbutyl)dithiirane 1-oxide (1), while the 6-endo-oxide of 2 gave both 1 and its (1RS, 3RS)-isomer 10. Under similar reaction conditions, 2 yielded the first isolable, unoxidized dithiirane, 3-phenyl-3-(1,1,3,3-tetramethyl-4-oxo-4-phenylbutyl)dithiirane (3). The dithiirane 3 was also obtained by treatment of 2 with NaOCl–NaClO4. The X-ray structure analyses were performed for 1, 3, and 10. Treatment of unsymmetrical 8,8-dimethyl-1,9-diphenyl-10,11-dithiatricyclo[7.1.1.02,7]undeca-2,4,6-triene with NaOCl–NaClO4gave 3-[1-(o-benzoylphenyl)-1-methylethyl]-3-phenyldithiirane selectively in good yield. However, 1,3-dithietanes, prepared from adamantane-2-thiones, failed to give the corresponding dithiiranes by treatment with 2KHSO5·KHSO4·K2SO4 or NaOCl–NaClO4. The dithiirane 3 thermally isomerized to 2,2,4,4-tetramethyl-1,5-diphenyl-8-oxa-6,7-dithiabicyclo[3.2.1]octane probably via 2,2,4,4-tetramethyl-1,5-diphenyl-5-thioxo-1-pentanone S-sulfide.

Episulfidation of trans‐Cyclooctene with an 1,2,4‐Oxadithiolane

“…[19] Nonetheless, besides diphenyldithiirane (IV), also its open-ring isomer thiobenzophenone S-sulfide (V) has been invoked in the thermal fragmentation of tetraphenyl-1,2,4-trithiolane into thiobenzophenone and elemental sulfur. [20] On the basis of the afore-mentioned, we speculate that the intermediates II and IV act as sulfurtransfer agents in this episulfidation of the strained cycloalkene 3.…”

The dimer, trimer and 1,2,4-trithiolane of adamantanethione

“…He also observed that (I) undergoes dimerization and trimerization to give compounds (II) and (III) when treated with methanesulfonic acid (cf. Ishii et al, 1997). The dimer, (II), was also formed in high yields in reactions of (I) with ,unsaturated carbonyl compounds, which act as heterodienes (Katada et al, 1984a), as well as with derivatives of 2-hydroxybenzyl alcohol and with hydrazonoyl chlorides (Katada et al, 1984b).…”

Adamantanethione

“…5 Preparative Methods: the most frequently applied method to prepare the title reagent is the thionation of adamantanone with P 4 S 10 in pyridine. 2,6,7 Other thionation reagents such as Purification: column chromatography (silica gel, petroleum ether/dichloromethane); sublimation. 4,11 Handling, Storage, and Precautions: camphoraceous odor; stable at low temperature (dry ice) under inert gas, decomposes slowly at room temperature in contact with air; safe in handling.…”

“…Dimerization of 1 leading to 1,3-dithiethane 3 (68 %) occurs smoothly in methane sulfonic acid at rt (eq 2). 2,7 The dimer 3 is formed as a minor product in attempted hetero-Diels-Alder reactions of,-unsaturated ketones with 1 in the presence of hydroquinone at 180 °C. 15 The dimer 3 appears as the major product when a mixture of 1 and 2-(hydroxymethyl)-or 2-[(N,Ndimethylamino)methyl]phenols in xylene are heated at 180 °C in the presence of catalytic amounts of 1,4-hydroquinone.…”