4- Hydroxy-1,2-dithiolane

The procedure for the preparation of a dithiolane from a hydroxy-methylene derivative of a ketone and ethylene dithiotosylate (ethane-1,2-dithiol di-p-toluenesulfonate) can be varied to produce dithianes when the latter reagent is replaced by trimethylene dithiotosylate.8,4 The dithiotosylates also react with enamine derivatives to produce dithiaspiro compounds.4,5... 

I46a The condensation of the dithioacids with a-halogen ketones does not always produce j3-keto dithioesters (223). Somewhat surprisingly in several instances the reaction under mild alkaline conditions resulted in spontaneous ring closure to form the 4-hydroxy-l,3-dithiolan-2-ylidene derivatives, which in general under acidic treatment yield l,3-dithioI-2-ylidene derivatives (Section III, A, 2,c).l46b... 

Another modification of a cyclopentene moiety was achieved by the cycloaddition reaction of the 1,3-dithiolane derivative 483 with singlet oxygen O2 to form the endoperoxide 484, which upon treatment with either triethyl-amine, triphenylphosphine, or bromine gave the corresponding hydroxy ketone 485, a mixture of the epoxide 486 and the enonc 487, or a mixture of isomeric adducts 488 and 489, respectively (Scheme 69) <1995JOC1333>. 

Im Gegensatz dazu fiihrt die Reduktion von 4-Hydroxymethyl-2-phenyl-l,3-dithiolan mit Natrium/fl. Ammoniak und Athanol zu 1 -Hydroxy-propandithiol-(2,3)A ... 

Elimination. Conjugated enynes and styrenes are formed from p-hydroxy sulfides that are derived from 2-alkynyl- and l-aryl-l,3-dithiolanes. The reaction is considered as... 

Die Herstellung der Alkalimctalldithiolate konnte einfacher erfolgen. Die Umesterung von 2-Ethoxy-l,3-dithiolan mit Desoxyribonucleosiden dient dem Schutz der 5 -Hydroxy-Gruppe298. 

Position 2 of the ergoline skeleton is highly suitable for synthetic modification of EA by both electrophilic and radical substitution. Many modifications have been reviewed by Rutschmann and Stadler (1978) chlorination, bromination and iodination, nitration and reduction of nitro derivatives to amino derivatives and reaction with 2-methoxy-l, 3-dithiolane affording an intermediate which can be desulfurised to a 2-methyl derivative. Troxler and Hofmann (1959) described the oxidation of lysergic acid diethylamide (LSD) to 2-oxo-3-hydroxy-2, 3-dihydrolysergic acid diethylamide. 

Chloromethyl Oxirans react with barium hydroxide that is saturated with HjS to give 3-hydroxy-thietans. Aldehyde-dimedone adducts give thietans (80) when treated with SCl2. Ring-contraction of a dithiolan with tris(diethylamino)-phosphine gives a 2-propyl-thietan. Treatment of (81) with triphenylphosphine and diethyl azodicarboxylate gives (82). 

Woodward has now reported reliable procedures for the preparation of trimethylene and ethylene dithiotoluene-jp-sulphonates, reagents used in the formation of dithians and dithiolans from active methylene compounds, including those adjacent to a carbonyl group activated by prior hydroxy-methylene or enamine formation. Applications include carbon-carbon bond cleavage and ketone transposition (Scheme 148). 

Literature on the stability of individual cydk disulfides covers (i) compounds that polymerize on standing like 3,3-dimethyl-1 -dithiolaiK [124,12, 3-hydroxy-l,2-dithiolane [126] and iV-phenyl-4-oxo-5-aza-l,2-dithia-cyclohexane [127,128] ii) compoimds which polymerizes on heating such as dibenzo-lA5,6-tetrathiocin [129] and iii) compounds that polymeixK in neat form when a catalyst is added, such as cis-l,2-dithiacyclohex-4-aie [130] and l-oxa-4,5-dithiacycloheptane [13, 119, 130]. Detailed study of the stability of cyclic disulfides towards polymerization revealed that 1,2-dithiai are the only class of simple cyclic disulfides that is thermodynamically staUe with respect to its polymerization in the melt or as concentrated solutions [131]. 

An empirical formula C3H6O2S2 has been deduced for both compounds from elemental analysis and judging from the results of the UV, IR, NMR and MS spectra analyse, both compounds were apparently either of the cis- and trans-isomers of 4-hydroxy-l,2-dithiolane-1-oxide. 

A possible mechanism of this oxidative desulfurization is shown in as Fig. 6, namely, the central sulfur atom in the v-trithiane ring is oxidized to form sulfone, in which an intramolecular nucleophillic rearrangement takes place to give the 1,2-dithiolane ring and SO2. The intermediate, 5-hydroxy-l,2,3-trithiane in this reaction is a new v-trithiane compound. And, as we will mention later, it is a compound of importance as the base of insecticidal active derivatives. As there was no report on the crystal structure of v-trithiane, the stereochemical structure was investigated by X-ray analysis. ... 

BRUGIEROL, TRANS- AND CIS-4-HYDROXY-l,2-DITHIOLANE-l-OXIDE, Tetrahedron Lettersy 29 2959 972). 

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