78640-99-0

Upstream product

• 563-80-4 3-methyl-butan-2-one 
• 74-90-8 hydrogen cyanide 
• 4111-10-8 (+/-)-2-hydroxy-2,3-dimethylbutanenitrile 
• 78641-06-2 (S)-2-acetoxy-2,3-dimethylbuttersaeure-aethylester 
• 72-18-4 L-valine 
• 17407-55-5 (S)-2-Hydroxy-3-methylbutanoic acid 
• 89053-56-5 (2S-cis)-2-(1,1-dimethylethyl)-5-(1-methylethyl)-1,3-dioxolan-4-one 
• 1155842-22-0 (S)-2,3-dimethyl-2-(trimethylsilyloxy)butanenitrile 
• 883726-88-3 2,3-dimethyl-2-((trimethylsilyl)oxy)butanenitrile 
• 805228-82-4 (R)-2,3-dimethyl-2-(trimethylsilyloxy)butanenitrile 
• 78641-05-1 (-)-(R)-2-isopropyl-2-methyl-3-oxobuttersaeure-aethylester 
• 1522-46-9 ethyl 2-isopropylacetoacetate 
• 78641-00-6 2-isopropyl-2-methyl-3-oxobuttersaeure-aethylester 

Downstream Products

• 434952-60-0 (S)-2-Hydroxy-2,3-dimethyl-butyric acid benzyl ester 
• 92735-41-6 (S)-2,3-Dimethyl-1-(tosyloxy)-2-butanol 
• 58050-56-9 C₂₈H₄₄O₂ 
• 120707-37-1 24(S)-hydroxyvitamin D₂ 
• 434952-61-1 (S)-2-((S)-2-tert-Butoxycarbonylamino-propionyloxy)-2,3-dimethyl-butyric acid benzyl ester 

Relevant academic research and scientific papers

ASYMMETRIC PROCESS FOR MAKING SUBSTITUTED 2-AMINO-THIAZOLONES

The invention provides two process for synthesizing substituted aminothiazolone compounds as inhibitors of 11-β-hydroxy steroid dehydrogenase type 1. The processes allow the stereoselective synthesis of the desired compounds without the use of stoichiometric amounts of chiral catalysts.

Two asymmetric syntheses of AMG 221, an inhibitor of 11β- hydroxysteroid dehydrogenase type 1

(Chemical Equation Presented) Two asymmetric syntheses of AMG 221 (2), an inhibitor of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) discovered in our laboratories, are reported. One of the syntheses utilizes chiral trimethylsilyl cyanohydrin 12 as s

Method for making 24(S)-hydroxyvitamin D2

The invention provides a method for making 24(S)-hydroxyvitamin D2which is a stereospecific synthesis.

A stereospecific synthesis of 24(S)-hydroxyvitamin D2, a prodrug for 1α,24(S)-dihydroxyvitamin D2

This contribution describes the first stereospecific synthesis of 24(S)-hydroxyvitamin D2 (1), a metabolite of vitamin D2. This metabolite acts as a prodrug for 1α,24(S)-dihydroxyvitamin D2 (2), which is under development for treatment of various diseases characterized by cellular hyperproliferation. The key step of the synthesis involves the Wittig-Horner olefination of (S)-2,3-dimethyl-2-triethysilyloxybutyraldehyde (17) and a vitamin D2 phosphine oxide derivative (22). The synthesis of the requisite aldehyde started with the commercially available L-(+)-valine and was completed in seven steps. The vitamin D2 phosphine oxide derivative was synthesized in seven steps starting from vitamin D2.

(αMe)Hyv: Chemo-enzymatic synthesis, and preparation and preferred conformation of model depsipeptides

By a chemo-enzymatic approach we performed a large-scale, stereoselective synthesis of the Cα-methylated α-hydroxy acid L-(αMe)Hyv. We also prepared model depsipeptides based on this sterically demanding residue in combination with the α-amino

Enzyme-catalyzed synthesis of (R)-ketone-cyanohydrins and their hydrolysis to (R)-α-hydroxy-α-methyl-carboxylic acids

(R)-Ketone-cyanohydrins (R)-2 are obtained with high enantioselectivity from aliphatic ketones 1 and HCN in organic solvents using (R)-oxynitrilase ( EC 4.1.2.10) as catalyst. Acid catalyzed hydrolysis of the cyanohydrins (R)-2 affords the corresponding (R)-α-hydroxy-α-methyl-carboxylic acids (R)-3 without measurable racemization.

PHEROMONE SYNTHESIS-63 SYNTHESIS OF BOTH THE ENANTIOMERS OF 2,3-DIHYDRO-2-ISOPROPYL-2,5-DIMETHYLFURAN, A SEX SPECIFIC COMPOUND IN FEMALES OF THE BEETLE HYLECOETUS DERMESTOIDES L

Both the enantiomers of 2,3-dihydro-2-isopropyl-2,5-dimethylfuran were synthesized employing the Sharpless asymmetric epoxidation reaction.The (R)-(-)-enantiomer of this cyclic enol ether was also synthesized from (R)-(-)-linalool.

Note on the Determination of the Absolute Configuration of (+)-2-Hydroxy-2,3-dimethylbutyric Acid

Chemical correlation of the title compound 1 with (S)-3-isopropyl-3-methyl-5-trimethylsilyl-4-penten-2-one (2) showed (+)-1 to have (S)-configuration.Key step was the Baeyer-Villiger oxidation of a very hindered, optically active methyl keton to the corresponding acetoxy compound with trifluoroperacetic acid using slightly modified buffer conditions.It is found, that the erythro/threo assignment of an α,α-disubstituted β-hydroxyester intermediate can be based on the observation, that the 1H-NMR signal of H-C(β) of the erythro isomer appears at lower field than that of the threo isomer.