21504-01-8

Upstream product

• 81968-49-2 1-(2-phenyl-hexahydro-pyrrolo[1,2-c]imidazol-3-yl)-propan-1-one 
• 6175-45-7 2,2-diethoxyacetophenone 
• 98-86-2 acetophenone 
• 925-90-6 ethylmagnesium bromide 
• 2439-43-2 (2RS)-2-phenylbutanal 
• 872045-33-5 (1-methoxybut-1-en-2-yl)benzene 
• 100-52-7 benzaldehyde 
• 156365-81-0 (2S,4S,5R)-4-methyl-2-(1-oxo-1-phenyl)methyl-5-phenyl-3-tert-butoxycarbonyloxazolidine 
• 682352-10-9 (1S,2R,3S,5R,2'S)-6,6-dimethyl-3-(2'-ethoxy-1'-phenyl-1'-oxo-2'-ethylsulfanyl)-2-(O-t-butyl-dimethylsilyl-hydroxymethyl)-bicyclo[3.1.1]heptane 
• 682352-08-5 (1S,2R,3S,5R,2'S)-6,6-dimethyl-3-(2'-ethoxy-1'-phenyl-1'-oxo-2'-ethylsulfanyl)-2-hydroxymethyl-bicyclo[3.1.1]heptane 
• 682352-13-2 (1S,2R,3S,5R,1'S,2'R)-6,6-dimethyl-3-(1'-ethoxy-2'-phenyl-2'-hydroxy-1'-butylsulfanyl)-2-(O-t-butyl-dimethylsilyl-hydroxymethyl)-bicyclo[3.1.1]heptane 
• 858658-57-8 (1S,2R,5R,7S,9R,1'R)-5-(1'-hydroxy-1'-phenyl-1'-propyl)-10,10-dimethyl-4-oxa-6-thia-tricyclo[7.1.1.0^2,7]undecane 
• 168784-83-6 (1S,2R,4S,6S,7R)-4-((R)-1-Hydroxy-1-phenyl-propyl)-7,10,10-trimethyl-3-oxa-5-aza-tricyclo[5.2.1.0^2,6]decane-5-carboxylic acid tert-butyl ester 
• 89616-54-6 (R)-1-Phenyl-1-((2S,4aR,7R,8aS)-4,4,7-trimethyl-hexahydro-1-oxa-3-thia-naphthalen-2-yl)-propan-1-ol 

Downstream Products

• 89616-49-9 (R)-2-hydroxy-2-phenyl-butyric acid methyl ester 
• 3966-31-2 (R)-2-hydroxy-2-phenylbutyric acid 
• 24256-91-5 (S)-2-hydroxy-2-phenylbutanoic acid 
• 2404-42-4 (S)-(-)-2-phenyl-butane-1,2-diol 
• 90925-48-7 2-phenylbutane-1,2-diol 

Relevant academic research and scientific papers

Cascade annulative π-extension for the rapid construction of carbazole based polyaromatic hydrocarbons

A Br?nsted acid catalyzed cascade benzannulation strategy for the one-pot synthesis of densely populated poly-aryl benzo[a]carbazole architectures is disclosed from easily affordable fundamental commodities. The efficacy of this technique was further validated via the concise synthesis of structurally unique carbazole based poly-aromatic hydrocarbons. Furthermore, the photo-physical properties of the synthesized compounds are thoroughly investigated.

A simple primary amine catalyst for enantioselective α-hydroxylations and α-fluorinations of branched aldehydes

A new primary amine catalyst for the asymmetric α-hydroxylation and α-fluorination of α-branched aldehydes is described. The products of the title transformations are generated in excellent yields with high enantioselectivities. Both processes can be performed within short reaction times and on gram scale. The similarity in results obtained in both reactions, combined with computational evidence, implies a common basis for stereoinduction and the possibility of a general catalytic mechanism for α-functionalizations. Promising initial results in α-amination and α-chlorination reactions support this hypothesis.

Catalytic asymmetric dihydroxylation of enamides and application to the total synthesis of (+)-tanikolide

Asymmetric dihydroxylation of β,β- disubstituted enamides afforded chiral tertiary-alcohol-containing α-hydroxyaldehydes and 1,2-diols with high enantioselectivity (see scheme). This method was applied to the total synthesis of the antifungal natural prod

Enantioselective synthesis of either enantiomer of α-alkyl-α- hydroxy-α-phenylacetic acids using chiral auxiliaries

The enantioselective synthesis of either enantiomer of α-alkyl- α-hydroxy-α-phenylacetic acids was achieved by using 2-acyloxathianes 1a-c and the mixed acyl-S,O-acetals 7 and 8 as chiral auxiliaries, which can straightforwardly be prepared from (1R)-(-)-myrtenal. This procedure allowed the preparation of the title compounds in >95% enantiomeric excess (ee).

Camphor-derived 2-stannyl-N-Boc-1,3-oxazolidine: A new chiral formylanion equivalent for the asymmetric synthesis of 1,2-diols

Optically pure 2-tributylstannyl-N-Boc-1,3-oxazolidine 6, prepared from the camphor-derived aminoalcohol 5, was converted to diastereomerically pure 2-acyl derivatives 8 in three steps. Reaction of these ketones with Grignard reaagents at -78°C proceeded with high stereoselectivity affording tertiary carbinols which gave 1,2-diols with >96% ee after hydrolysis and reduction of the intermediate α-hydroxy aldehydes. A new deblocking procedure of the t-Boc group is also described.

N-Boc 2-acyloxazolidines: Useful precursors to enantiopure 1,2-diols via highly diastereoselective nucleophilic additions

N-Boc 2-Acyloxazolidines were synthesized from norephedrine and phenylglycinol. This preparation involves: (i) a transformation or the above β-amino alcohols into N-Boc 2-ethoxycarbonyloxazolidines, (ii) the formation of the corresponding Weinreb amides and, (iii) a reaction between these amides and organometallic reagents. Such diastereomerically pure heterocycles react cleanly with various nucleophilic reagents (Grignard reagents, sodium borohydride and allylsilane) to afford the corresponding alcohols. Treatment of these hydroxyoxazolidines with trifluoro acetic acid, followed by hydrolysis and reduction of the intermediate α-hydroxy aldehydes afforded 1,2-diols. The overall transformation exhibited in most cases a complete diastereoselectivity which can be explained by a chelated model for the nucleophilic addition.

Asymmetric Synthesis of Homochiral 1,2-Diols via N-Boc Oxazolidines

Diastereoisomerically pure N-Boc 2-acyloxazolidines were synthesized from phenylglyoxal and ethyl glyoxylate.Reaction of these heterocycles with Grignard reagents is highly stereoselective.Homochiral 1,2-diols were ultimately obtained after N-deprotection, hydrolysis and reduction of the intermediate α-hydroxy aldehyde.The asymmetric induction can be explained by a chelated model.

Asymmetric Syntheses Based on 1,3-Oxathianes. 2. Synthesis of Chiral Tertiary α-Hydroxy Aldehydes, α-Hydroxy Acids, Glycols (RR'C(OH)CH2OH), and Carbinols (RR'C(OH)CH3) in High Enantiomeric Purity

A chiral 1,3-oxathiane (5) prepared from (+)-pulegone in three steps is converted to diastereomerically pure equatorial 2-acyl derivatives by lithiation, condensation with aldehydes, and Me2SO oxidation.Reaction of the resulting ketones with Grignard reagents at -78 deg C again proceeds highly stereoselectively (diastereomer excess generally above 90percent) according to Cram's rule (cyclic model).The resulting tertiary carbinols when cleaved with NCS/AgNO3 give chiral tertiary α-hydroxy aldehydes, RR'C(OH)CHO, plus a mixture of epimeric sultines which may be readily reconverted to the starting oxathiane.The hydroxy aldehydes have been oxidized to chiral tertiary α-hydroxy acids, RR'C(OH)CO2H, and reduced to primary-tertiary glycols, RR'C(OH)CH2OH, and further to tertiary carbinols, RR'C(OH)CH3, all with over 90percent ee.The opposite enantiomers of these compounds (again >90percent ee) may be obtained by starting with a diastereomeric 1,3-oxathiane (6), also available from (+)-pulegone.The configurations of the chiral products may be deduced from the manner of preparation and the assumption that Cram's rule is valid and agree with prior assignments in the literature.

α-Hydroxyaldehyde and a process for preparing the same

An optically active or racemic α-hydroxyaldehyde represented by the general formula (2), STR1 wherein R1 represents a C6 -C14 aryl group, C1 -C10 alkyl group, C3 -C10 alkenyl group, C2 -C10 alkynyl group, C7 -C14 aralkyl group, or a group containing a functional group in the organic portion of said groups and R2 represents a C1 -C10 alkyl group, C2 -C10 alkenyl group, C2 -C10 alkynyl group, C7-C14 aralkyl group, C6 -C14 aryl group, or a group containing a functional group in the organic portion of these groups, which is an important intermediate for preparation of pharmaceuticals and agricultural chemicals, and prepared by allowing an optically active or racemic compound represented by the general formula (1), STR2 (wherein A represents a C6 -C14 aryl group or a C1 -C4 alkyl or alkoxy group- or halogen-substituted C6 -C14 aryl group and R1 is as defined above) to react with a Grignard reagent, and thereafter hydrolyzing the reaction product.

ASYMMETRIC SYNTHESIS BASED ON CHIRAL DIAMINES HAVING PYRROLIDINE RING

Various highly stereoselective asymmetric reactions based on chiral diamines having pyrrolidine ring are described.Some of these reactions have been successfully applied to the syntheses of natural products.