22038-58-0

Upstream product

• 67-56-1 methanol 
• 53993-41-2 (Z)-2-Chloro-but-2-enoic acid 
• 51171-63-2 methyl-2-chlorobut-3-enoate 
• 127-09-3 sodium acetate 
• 64-19-7 acetic acid 
• 186581-53-3 diazomethane 
• 26708-31-6 erythro-methyl 2,3-dichlorobutanoate 
• 111254-13-8 methyl (Z)-2,4,4-trichloro-2-butenoate 
• 70288-53-8 erythro 3-bromo-2-chloro-butenoate 
• 623-43-8 crotonic acid methyl ester 
• 162918-74-3 methyl 2-bromo-2-chloro-butanoate 
• 75-07-0 acetaldehyde 
• 21204-67-1 methyl (triphenylphosphoranylidene)acetate 
• 70288-53-8 2-Chlor-3-brombuttersaeure-methylester 

Downstream Products

• 600-12-4 (2R)-2-chlorobutanoic acid 
• 600-12-4 (S)-2-chlorobutyric acid 

Relevant academic research and scientific papers

Enoate reductase-mediated preparation of methyl (S)-2-bromobutanoate, a useful key intermediate for the synthesis of chiral active pharmaceutical ingredients

Enoate reductases belonging to the Old Yellow Enzyme (OYE) family were employed to develop a biocatalysed approach to methyl (S)-2-bromobutanoate, a key intermediate for the introduction of a particular stereogenic unit into the molecular skeleton of a certain class of chiral drugs. Methyl (Z)-2-bromocrotonate afforded, respectively, (S)-2-bromobutanoic acid (ee = 97%) and methyl (S)-2-bromobutanoate (ee = 97%) by baker's yeast fermentation and by OYE1-3 biotransformations. The bioreductions of other methyl 2-haloalkenoates were also considered. It was observed that the (Z)- and (E)-diastereoisomers of α-bromo unsaturated esters afforded the same enantiomer of the corresponding reduced product.

Syntheses of strychnos and aspidospermatan-type alkaloids. 8. Selective total syntheses of mossambine and 14-epi-mossambine by a radical cyclization reaction

Mossambine (6) was obtained by a six-step reaction sequence from the indoloazepine ester 7. Radical cyclization of the tetracyclic vinyl iodide 12a provided a racemic pentacyclic ketone 16E, which could be converted to either enantiomer by condensation with (S or R)-N,S-dimethyl-S-phenylsulfoximine and selective pyrolysis of the resulting diastereomeric alcohols 18 and 19 or 20 and 21. Selective reductions of the resolved (or racemic) ketone 16E profided mossambine (6) and its hydroxy epimer 17.

Stereoselective dehydrobromination of alkyl α-Br α-Cl-carboxylates

(Z)-Alkyl α-Cl-α,β-unsaturated esters are prepared in excellent yields by stereoselective dehydrobromination of alkyl α-Br-α-Cl-carboxylates with LiCl-Li2CO3 in dimethylformamide.

Reaction of Benzeneseleninyl Chloride with Olefins in the Presence of a Lewis Acid. A Novel One Step Vinylic Chlorination

In the presence of aluminum chloride benzeneseleninyl chloride was found to be an exellent vinylic chlorinating reagent of olefins under mild conditions.However, such olefins as styrene, trans-stilbene, and trans-1-phenylpropene afforded dichloro adducts under similar conditions.A plausible reaction mechanism involving positive chlorine intermediate is proposed.

ADDITION OF CHLORINE, BROMINE AND BROMINE CHLORIDE TO SOME α,β-UNSATURATED METHYL ESTERS

The additions of chlorine, bromine and bromine chloride to trans methyl 2-butenoate 1, trans methyl 2-methyl-2-butenoate 2 and methyl 3-methyl-2-butenoate 3 under ionic conditions were studied.Bromine chloride addition always gave as a major regioisomer the 2-bromo-3-chloro compound, almost quantitatively in the case of 3.The mechanism of bromonium ion ring-opening (SN1 or SN2) is discussed with respect to the double bond substitution and regioisomer proportions.The dihalo products were identified by MS, 1H and 13C NMR.