74939-90-5

Upstream product

• 608-40-2 rac-2,3-dimethylsuccinic acid 
• 105592-22-1 acetoxy-4 dimethyl-2,5 butanoate de ethyle 
• 39637-99-5 (S)-(+)-2-methoxy-2-trifluoromethyl-2-phenylacetyl chloride 
• 125001-42-5 etythro-2,3-dimethylbutane-1,4-diyl diacetate 
• 28306-68-5 dimethyl (+/-)-2,3-dimethylbutanedioate 
• 13545-04-5 2,3-dimethylsuccinic acid 

Downstream Products

• 57340-48-4 meso-2,3-dimethyl-1,4-bis-(toluene-4-sulfonyloxy)-butane 
• 127593-78-6 (+/-)-4-benzyloxy-2,3-dimethylbutan-1-ol 
• 125001-42-5 etythro-2,3-dimethylbutane-1,4-diyl diacetate 
• 131479-19-1 (+/-)-Lasiol 
• 127553-95-1 C₁₉H₂₄O₃S 
• 57340-48-4 racem.-2,3-dimethyl-1,4-bis-(toluene-4-sulfonyloxy)-butane 

Relevant academic research and scientific papers

A phosphine-free iron complex-catalyzed synthesis of cycloalkanes: Via the borrowing hydrogen strategy

Herein we report a diaminocyclopentadienone iron tricarbonyl complex catalyzed synthesis of substituted cyclopentane, cyclohexane and cycloheptane compounds using the borrowing hydrogen strategy in the presence of various substituted primary and secondary 1,n diols as alkylating reagents. Deuterium labeling experiments confirm that the diols were the hydride source in this cascade process. This journal is

Enzymatic dissymmetrization of meso-2,3-dimethylbutane-1,4-diol and its diacetate. Synthesis of scalemic (-)-lasiol

Acylation of meso-2,3-dimethylbutane-1,4-diol with vinyl acetate in the presence of porcine pancreatic lipase (PPL) leads to the dextrorotatory monoacetate of the above diol with enatiomeric excess (ee) 58-64 percent. Absolute configuration of this scalemic specimen was determined by its sequential transformation to levorotatory lasiol, a metabolite of the Lasius ants. Partial hydrolysis of the corresponding meso-diacetate, mediated by PPL or by the Pseudomonas sp. lipase affords the monoacetate of opposite configuration with ee 72-86 percent, a formal intermediate in the synthesis of (3S,4R)-faranal. Other microbial lipases used are distinctive in low chemoselectivity.

Stereospecificite de l'addition de Michael d'enethiolates avec les enones acyliques

1,4-Addition reaction of lithiated dithioesters with acyclic β-substituted E enones affords diastereomeric 5-oxo-alkanedithioates.Anti configuration was assigned to yhe major diastereoisomer by chemical correlation.This stereochemistry depends on the configuration of the prochiral partners.The cis/trans ratio of intermediate enethiolates was analyzed by trapping experiments.Two cases of highly selective cis deprotonation of dithioesters were observed.Michael addition with E-enones (3-penten-2-one, chalcone) occurs with high stereospecificity : anti/syn product ratios are identical to the cis/trans enethiolate ratios.A pseudo-cyclic transition state is proposed with substituents of the enone C-C double bond occupying favorable equatorial positions.The 1,4-addition reaction is kineticaly controlled.In contrast to ester enolates, enethiolates allow the use of enones without the need of tertiobutyl or phenyl groups.The observed diastereoselectivity (ratio anti/syn up to 95:5) offers a new means of creation of two vicinal carbon substituted asymmetric centers by carbon-carbon bond formation in the acyclic series.Poor selectivities were however observed when using unsaturated diesters as acceptors.