135789-36-5

Upstream product

• 95061-46-4 (R)-1,1,2-triphenylethane-1,2-diol 
• 135789-37-6 (R)-2-hydroxy-1,2,2-triphenylethyl propionate 
• 75-77-4 chloro-trimethyl-silane 
• 135822-23-0 (R)-1-(trimethylsilyloxy)-1-<1,2,2-triphenyl-2-(trimethylsilyloxy)ethoxy>-1-propene 

Downstream Products

• 135789-40-1 (1R)-1,2,2-triphenyl-2-(trimethylsilyloxy)ethyl (2R,3S)-3-hydroxy-2,4,4-trimethylpentanoate 
• 135789-39-8 (1R)-1,2,2-triphenyl-2-(trimethylsilyloxy)ethyl (2R,3R)-2,4-dimethyl-3-hydroxypentanoate 
• 135789-39-8 (2S,3S)-3-Hydroxy-2,4-dimethyl-pentanoic acid (R)-1,2,2-triphenyl-2-trimethylsilanyloxy-ethyl ester 
• 135789-38-7 (1R)-1,2,2-triphenyl-2-(trimethylsilyloxy)ethyl (2R,3S)-3-hydroxy-2-methyl-3-phenylpropanoate 
• 36041-79-9 (S)-3-Hydroxy-2-methyl-3-phenyl-propionic acid 
• 135789-38-7 (1R)-1,2,2-triphenyl-2-(trimethylsilyloxy)ethyl (2S,3R)-3-hydroxy-2-methyl-3-phenylpropanoate 
• 135789-38-7 (2S,3S)-3-Hydroxy-2-methyl-3-phenyl-propionic acid (R)-1,2,2-triphenyl-2-trimethylsilanyloxy-ethyl ester 

Relevant academic research and scientific papers

(R)-1,2,2-Triphenyl-2-(trimethylsiloxy)ethyl Propionate: anti-Selective and Diastereofacially Selective Aldol Addition; Diastereoselective Silylation and Alkylation

The propionates (R)-5 and (R)-6 which are derived from the readily available chiral auxiliary reagent (R)-triphenylglycol (4) have been applied in stereoselective aldol reactions.Whereas the enolate 7 and the silyl ketene acetal 12, both generated from the ester (R)-6, display only moderate diastereoselectivity when treated with benzaldehyde, β-hydroxyesters 8b and 16a, b are formed in diastereomeric ratios up to 95:5 (ratio of the main product to the sum of all other stereoisomers) when the propionate (R)-5 is subsequently deprotonated, transmetalated into the zirconium enolate and allowed to react with aldehydes.Alkaline hydrolysis or reduction with LiAlH4 enables the conversion of the adducts 8a and 16a, b into the carboxylic acid 15a and the diols 17a, b, respectively, which are obtained in >95percent e.e.When the enolate 13 is treated with chlorotrimethylsilane, carbon silylation occurs so that the α-silyl propionate 18a is formed diastereoselectively.On the other hand, alkylations of the enolate 13 with primary alkyl halides display only moderate diastereoselectivities.The structures of the propionate 5, the α-silyl ester 18a, and the alkylation product 18b are proven unambiguously by crystal structure analyses. - Key Words: Aldol reaction / Chiral enolate / Mandelic acid