Synthesis of trimethyl .alpha.-keto trithioorthoesters and dimethyl .alpha.-keto dithioacetals by reaction of esters with tris(methylthio)methyllithium
摘要:
A complete study has been made of the reaction of tris(methylthio)methyllithium with aromatic, heteroaromatic, and aliphatic esters. It is a one-pot reaction that despite its complexity, and depending on the reagent ratios, the reaction conditions, and the possible use of additional reagents (N-(methylthio)phthalimide or BuLi), can supply easily, in excellent and reproducible yields, the trimethyl alpha-keto trithioorthoesters 3 or, alternatively, the dimethyl a-keto dithioacetals 4. The reaction mechanism has been elucidated.
Reactions of Group IV organometallic compounds. Part XI. Some insertion reactions of alkylsilyl and alkylstannyl sulphides
作者:Kenji Itoh、Kimishige Matsuzaki、Yoshio Ishii
DOI:10.1039/j39680002709
日期:——
Reaction of trimethylsilyl sulphide with phenyl isocyanate gives a 1 : 1 insertion product, but subsequent insertion of phenyl isocyanate takes place readily in the case of trialkylstannyl sulphide, to produce triphenyl isocyanurate. When chloral is used as a reactant for trialkyltin sulphides, substitution of all three chlorine atoms occurs, to afford trialkyltin chloride and (RS)3C·CHO, although
A study was made of the isomerization reaction of a great variety of trimethyl alpha-keto trithioorthocarboxylates to alpha,alpha-bis(methylthio) thiolcarboxylates, intermediates of high synthetic value for the synthesis of alpha-arylpropionic acids. The reaction was carried out In methylene chloride in the presence of catalytic amounts of trityl perchlorate or methanesulfonic acid and was complete in 2 h at rt. In most of the investigated cases the result was positive, the yields usually being greater than 90%. Also the reaction mechanism was subjected to an experimental study.
Synthesis of Trimethyl α-Keto Trithioorthoesters and Dimethyl α-Keto Dithioacetals by Reaction of Acyl Chlorides, Anhydrides, Thiol Esters, and <i>N</i>,<i>N</i>-Dimethylamides with [Tris(methylthio)methyl]lithium
Synthesis of trimethyl .alpha.-keto trithioorthoesters and dimethyl .alpha.-keto dithioacetals by reaction of esters with tris(methylthio)methyllithium
A complete study has been made of the reaction of tris(methylthio)methyllithium with aromatic, heteroaromatic, and aliphatic esters. It is a one-pot reaction that despite its complexity, and depending on the reagent ratios, the reaction conditions, and the possible use of additional reagents (N-(methylthio)phthalimide or BuLi), can supply easily, in excellent and reproducible yields, the trimethyl alpha-keto trithioorthoesters 3 or, alternatively, the dimethyl a-keto dithioacetals 4. The reaction mechanism has been elucidated.
A Simple and High Yield General Route to Methyl α-Oxo Thiolcarboxylates
Methyl α-oxo thiolcarboxylates (aliphatic, aromatic and heteroaromatic) are obtained in good to excellent yields by hydrolysis of the corresponding trimethyl α-oxo trithioorthoesters with N-bromosuccinimide in aqueous THF or with HgO/35% aqueous HBF4 ves.