1040922-81-3Relevant academic research and scientific papers
First stereoselective synthesis and assignment of the absolute configuration of the nebracetam eutomer and derivatives
Lima, Evanoel C.,Domingos, Jorge L.O.,Dias, Ayres G.,Costa, Paulo R.R.
, p. 1161 - 1165 (2008)
(-)-Nebracetam 1 was stereoselectively prepared for the first time, allowing the determination of its absolute configuration as (R). The pivotal intermediate in the synthesis, 1-benzyl-4-[(S)-2,2-dimethyl-1,3-dioxolan-4-yl]-pyrrolidin-2-one 6, was previously obtained in 60% yield and 90% ee from an enoate derived from d-mannitol. Two approaches were investigated to synthesize (R)-(-)-nebracetam 1 and analogues 4 and 5 from 6. Compound 6 was transformed into WEB-1868 2. Mesylation of the hydroxyl group in 2, followed by nucleophilic substitution with azide and reduction led to target 1. Compounds 4 and 5 were synthesized by using morpholine and N-methyl piperazine as nucleophiles. Compounds 4 and 5 were also prepared, in higher yields and similar ee, through the reductive amination of aldehyde 10, obtained in two steps from 6.
Process for the enantioselective preparation of pregabalin
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Page/Page column 13-14, (2009/02/10)
The invention provides a new enantioselective process for the preparation of (S)-pregabalin, or a pharmaceutical acceptable addition acid salt comprising: acid hydrolysis of the dioxolan ring of a chiral compound of general formula (I) to obtain compound
