26728-22-3Relevant academic research and scientific papers
CYCLIC DITHIO-CARBENIUM ION SALTS AND THEIR CONVERSION TO KETENE DITHIOACETALS
Okuyama, Tadashi
, p. 2665 - 2666 (1982)
1,2-Ethanedithiol and 1,3-propanedithiol were treated with perchloric acid in acetic anhydride to give 2-methyl-1,3-dithiolan-2-yl and 2-methyl-1,3-dithian-2-yl perchlorates, respectively, which were converted to ketene dithioacetals by deprotonation with tertiary amines.
A short and efficient synthesis of ketene O,O-and S,S-acetals under focused microwave irradiation and solvent-free conditions
Diaz-Ortiz, Angel,Prieto, Pilar,Loupy, Andre,Abenhaim, David
, p. 1695 - 1698 (1996)
A new methodology leading to ketene O,O-and S,S-acetals is reported. The title compounds were prepared from the corresponding halogenated precursors under microwave irradiation in the absence of solvent within 5-25 minutes with excellent yields. Yields obtained under microwaves are by far the best when compared to those obtained by ultrasound or classical heating in the same conditions of time and temperature.
Exploratory Synthetic Studies Involving the Tricyclo2,8>tetradecane Ring System Peculiar to the Cyathins
Dahnke, Karl R.,Paquette, Leo A.
, p. 885 - 899 (2007/10/02)
Following an improved preparation of 2-methylene-1,3-dithiolane, this ketene acetal was shown to undergo inverse-electron-demand Diels-Alder cycloaddition to tropone.Regiocontrolled copper hydride reduction and resolution via sulfoximine adducts was readily achieved to give (-)-9.Addition to 9 of the chiral nonracemic vinyl bromides 21 and 22 proceeded with endo capture of the nucleophilic vinyllithium to give carbinols that underwent anionic oxy-Cope rearrangement at somewhat elevated temperatures.The sigmatropic event delivered cis,syn,cis-tricyclo2,8>tetradecenones possessing structural frameworks related to the cyathins.Once 31 was in hand, it proved an easy matter to introduce added unsaturation and oxygen substituents.The tendency of certain derivatives for transannular cyclization was made quite apparent.Attempts to introduce a C(6)-α-methyl substituent was not achieved, chiefly as the result of the overall molecular concavity of this class of intermediates.A variety of reactions aimed at enhancing the level of functionality in rings B and C was explored and processes conducive to the attainment of these goals were developed.
Ketene thioacetals from α-chloromercaptals
Bellesia,Boni,Ghelfi,Pagnoni
, p. 3179 - 3184 (2007/10/02)
Excellent yields of ketene thioacetals are obtained from 2-(1- chloroalkyl)-1,3-dithiolanes or 2-(1-chloroalkyl)-1,3-dithianes.
Isolation of Dithiolanylium Salts and Their Conversion to Ketene Dithioacetals and Ortho Esters
Okuyama, Tadashi,Fujiwara, Wataru,Fueno, Takayuki
, p. 453 - 456 (2007/10/02)
Various 2-substituted 1,3-dithiolan-2-ylium perchlorates (1) were prepared by the reaction of 1,2-ethanedithiol with acyl chlorides in the presence of perchloric acid.Treatments of 1 with triethylamine gave 2-alkylidene-1,3-dithiolane (2) when the 2-substituent was a primary or secondary alkyl group. 2-Aryl derivatives of 1 were converted to ortho esters by the reaction with methanol in the presence of silver nitrate. 1,3-Dithian-2-ylium perchlorates and 2-alkylidene-1,3-dithianes were also prepared similarly from 1,3-propanedithiol.
