90026-01-0

Upstream product

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

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.

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.

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.