On March 24, 2000, Fukuzawa, Shin-ichi; Matsuzawa, Hiroshi; Yoshimitsu, Shin-ichi published an article.Recommanded Product: (S)-4-Isopropyl-5,5-dimethyloxazolidin-2-one The title of the article was Asymmetric Samarium-Reformatsky Reaction of Chiral α-Bromoacetyl-2-oxazolidinones with Aldehydes. And the article contained the following:
The samarium(II) iodide mediated asym. Reformatskii-type reaction of chiral bromoacetyloxazolidinones I (R = Me2CH, Ph, PhCH2; R1 = H, Me, Ph) with various aldehydes R2CHO [R2 = Me2CH, Et2CH, c-C6H11, Me3C, Me(CH2)6, PhCH2CH2, Ph] was studied. A series of chiral 4-substituted 2-oxazolidinones and 5,5-disubstituted “SuperQuat” oxazolidinones were employed as chiral auxiliaries for α-bromoacetic acid. The reaction of I (R = Me2CH; R1 = H) with aldehydes R2CHO [R2 = Me2CH, Et2CH, c-C6H11, Me3C, Me(CH2)6, PhCH2CH2, Ph] gave β-hydroxy carboximides II [R = H; R1 = Me2CH; R2 = Me2CH, Et2CH, c-C6H11, Me3C, Me(CH2)6, PhCH2CH2, Ph] in 67-92% yields and in 64-99% diastereomeric excess. The majority of the reaction product derived from I (R = Me2CH; R1 = Ph) were highly crystalline; a single recrystallization of II [R = Me2CH; R1 = Ph; R2 = Me2CH, Me3C, Me(CH2)6, Ph] gave diastereomerically pure products with the β-hydroxy epimer not detectable by spectroscopic methods. The absolute configurations of the β-hydroxy carboximides were determined by comparison of the optical rotations of the corresponding known Et esters to the literature values. Hydrolytic cleavage of the appended β-hydroxy moieties from the auxiliary SuperQuats derivatives II (R = Me2CH; R1 = Me, Ph) was readily achieved under mild conditions using lithium hydroxide; the corresponding carboxylic acids and the returned SuperQuats were obtained in good yields without any evidence of racemization. The absolute configuration of the adduct derived from benzaldehyde was found to be R, with the samarium enolate formed by reduction of the bromoacetyl derivative favoring the transition state predicted from chelation control of the reagent; this is in analogy to the discussion that has been used for the corresponding titanium enolate. The stereochem. of the reaction may be explained by incorporating the Nerz-Stormes-Thornton chair transition structure model. The experimental process involved the reaction of (S)-4-Isopropyl-5,5-dimethyloxazolidin-2-one(cas: 168297-86-7).Recommanded Product: (S)-4-Isopropyl-5,5-dimethyloxazolidin-2-one
The Article related to hydroxy acid nonracemic stereoselective preparation, ester beta hydroxy stereoselective preparation, hydroxyalkanoyl oxazolidinone stereoselective preparation, asym reformatskii reaction bromoacetyl oxazolidinone aldehyde, stereoselective reformatskii reaction bromoacetyl oxazolidinone aldehyde and other aspects.Recommanded Product: (S)-4-Isopropyl-5,5-dimethyloxazolidin-2-one
Referemce:
Oxazolidine – Wikipedia,
Oxazolidine | C3H7NO – PubChem