90026-01-0

Upstream product

• 24347-58-8 (R,R)-2,3-butandiol 
• 98-59-9 p-toluenesulfonyl chloride 
• 6982-25-8 d,l-2,3-butanediol 
• 513-85-9 2,3-dihydroxybutane 
• 1029272-42-1 (2R,3S)-2,3-butanediol 
• 624-64-6 trans-2-Butene 
• 27126-76-7 [hydroxy(tosyloxy)iodo]benzene 
• 590-18-1 (Z)-2-Butene 

Relevant academic research and scientific papers

Highly Active and Selective Ethylene Oligomerization Catalyst and Method of Preparing Hexene or Octene Using the Same

This invention relates to a chromium complex compound for selective ethylene oligomerization including a chiral ligand, and to a method of selectively preparing 1-hexene or 1-octene from ethylene using the same.

Direct proline-catalyzed asymmetric α-aminoxylation of aldehydes and ketones

The direct proline-catalyzed asymmetric α-aminoxylation of aldehydes and ketones has been developed using nitrosobenzene as an oxygen source, affording α-anilinoxy-aldehydes and -ketones with excellent enantioselectivity. Reaction conditions have been optimized, and low temperature (-20 °C) was found to be a key for the successful α-aminoxylation of aldehydes, while slow addition of nitrosobenzene is essential for that of ketones. The scope of the reaction is presented.

SYNTHESIS OF OPTICALLY PURE COMPOUNDS BY ENANTIOTOPICALLY DIFFERENTIATING MONOACETALIZATION OF PROCHIRAL DIKETONES. PART II. FRAGMENTATION OF β-KETO-ACETALS

Treatment of β-keto-acetals, derived from non-enolisable β-diketones, with sulfonic acids in boiling benzene results in a smooth retro-Claisen-type fragmentation.The acetal-C-atom is thereby transformed into a carboxylic ester via a dialkoxycarbenium ion, which is dealkylated by the sulfonate counter-ion.Application of this reaction to the diastereomeric monoacetals 3 and 4, derived from cis-9-methyl-decalin-1,8-dione (1), followed by transesterification with CH3OH, yields optically pure 4-(2'-methyl-3'-oxocyclohexyl)butyrate 9 ((+)-9 from 3, (-)-9 from 4) and the monosulfonate of meso-2,3-butanediol (-)-13 (Scheme 2).Unexpected, this cleavage proceeds as well with monoacetal 26, obtained by acetalization of trans-9-methyl-decalin-1,8-dione (27) with 2,2-dimethyl-1,3-propanediol (Scheme 7).Some attempts, aiming at an isomerization of the cis- and trans-decalin derivatives 3 and 24, or 25 and 26, via the postulated carboxonium intermediate, were not successful.

Reaction Manifolds of Alkenes with benzene: Stereospecific syn-1,2-Ditosyloxylation of the Carbon-Carbon Double Bond and Other Processes

The treatment of various alkenes with benzene (1) in CH2Cl2 gives moderate yields of the corresponding vic-bis(tosyloxy)alkanes (2).When cis- and trans-2-butenes, cis- and trans-2-pentenes, cis-3-hexene, cis-4-octene, and cyclohexene are reactants, the tosyloxy ligands are introduced with syn stereospecifity.With cis- and trans-stilbenes, however, a mixture of meso- and dl-1,2-diphenyl-1,2-bis(tosyloxy)ethanes results from either alkene.Some alkenes react with 1 in a different way.Thus, trans-3-hexene and trans-4-octene with 1 give low yields of 2,5-bis(tosyloxy)-3-hexene and 3,6-bis(tosyloxy)-4-octene, respectively.Evidence is presented that the formation of the bis(tosyloxy)alkenes proceeds via initial oxidation of the trans alkenes by 1 to conjugated dienes and subsequent conjugate ditosyloxylation of the dienes.In a few cases, molecular rearrangements occur.Thus, norbornene with 1 gives 2,7-bis(tosyloxy)norbornane, among other products, while 1,1-diphenylethylene gives deoxybenzoin (major product) and (β,β-diphenylethenyl)phenyliodonium tosylate.The reaction of styrene with 1 depends on the medium; when CH2Cl2 is present, the product is 1-phenyl-1,2-bis(tosyloxy)ethane, but in the absence of solvent, the product is 1,1-bis(tosyloxy)-2-phenylethane.Most alkenes react with 1 to give p-toluenesulfonic acid as a byproduct, and, in rare instances, (iodoxy)benzene is obtained.A mechanism for the vic-ditosyloxylation of alkenes by 1, consistent with the observed syn stereospecificity, is proposed.