The reactions of Wittig reagents with episulfides gave symmetrical olefins and triphenylphosphine sulfide in moderate yields. The same olefins were obtained by reactions of Wittig reagents with elemental sulfur. These reactions might proceed through thiocarbonyl intermediates, the existence of which was confirmed by Diels–Alder reactions with dienes.
3,6‐Dihydro‐2H‐thiopyrans are important structural motifs both in organic synthesis and medicinal chemistry. A continuous flow‐process for the photochemical generation of thioaldehydes from phenacyl sulfides and the ensuing [4+2]‐cycloaddition with electron‐rich 1,3‐dienes was developed. The cycloadducts were obtained with excellent yields in short reaction times and much improved productivities as
Generation of ethyl thioxoacetate, a dienophilic thioaldehyde
作者:Christine M. Bladon、Irene E. G. Ferguson、Gordon W. Kirby、Alistair W. Lochead、Duncan C. McDougall
DOI:10.1039/c39830000423
日期:——
Ethoxycarbonylmethanesulphenyl chloride reacts with triethylamine to give the transient thioaldehyde, ethyl thioxoacetate, which has been trapped, in situ, by cycloaddition to various conjugated dienes.
A Novel Formation of Thiocarbonyl Compounds from Phosphorus Ylides with Cyclic Polysulfide as the Sulfuration Reagent
作者:Ryu Sato、Shin-ichi Satoh
DOI:10.1055/s-1991-26574
日期:——
The reaction of cyclic polysulfides, such as 5H-1,2,3,4-benzotetrathiepin and 6H-1,2,3,4,5-benzopentathiocin as the sulfuration reagent with relatively stable phosphorus ylides affords efficiently thiocarbonyl compounds such as thioaldehydes and thioketones, which further react with 2,3-dimethyl-1,3-butadiene or cyclopentadiene in situ to give various 5,6-dihydro-2H-thiopyrans and 2-thiabicyclo[2.2.1]hept-5-enes in satisfactory yields.
Generation of thioaldehydes from sodium thiosulphate S-esters (Bunte salts)
作者:Gordon W. Kirby、Alistair W. Lochead、Gary N. Sheldrake
DOI:10.1039/c39840000922
日期:——
Treatment of Buntesalts, ZCH2SSO3Na where Z is an electron-withdrawing group, with triethylamine and calcium chloride in the presence of cyclopentadiene or 2,3-dimethylbuta-1,3-diene gives the corresponding cycloadducts of the transient thioaldehydes, ZCHS; the cyclopentadiene adducts dissociate upon heating thereby allowing transfer of the thioldehydes to dimethylbutadiene.