221349-58-2Relevant articles and documents
Synthesis process of ezetimibe intermediate
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, (2016/10/24)
The invention discloses a synthesis process of an ezetimibe intermediate which is (2S,3S)-2-(4-(benzyloxy)phenyl)-1-(4-fluorophenyl)-4-oxoazetidine-3-carboxaldehyde (an intermediate E6); (s)-4-phenyl-2-oxazolone and ethyl malonyl chloride as raw materials are subjected to condensation through condensation catalysis of TMSCl and TBAF to obtain an intermediate E3, the intermediate E3 and N-(4-fluorophenyl)-4-benzyloxybenzylidene amine are subjected to condensation under catalysis of titanium tetrachloride to obtain an intermediate E4, the intermediate E4 is subjected to cyclization under catalysis of BSA and FBAF to produce beta-lactam intermediate E5, and then the intermediate E5 is reduced by DIBALH into the aldehyde intermediate E6. The raw materials adopted by the process are cheap and easy to obtain, a solvent is single, the reaction time is short, the production cost is low, the yield is high, the operation of production units is simple, and the synthesis process is suitable for industrialized production.
A PROCESS FOR THE PREPARATION OF AN ALDEHYDE BETA-LACTAM COMPOUND
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Page/Page column 31-32, (2010/09/17)
The invention relates to a process for the preparation of an aldehyde beta-lactam compound of formula (I), wherein P1 is H or a protecting group, useful in the preparation of ezetimibe, from a nitrone compound of formula (II). The nitrone compound Il is prepared by reacting 4-fluorophenylhydroxyloamine with OH- protected 4-hydroxybenzaldehyde. The nitrone compound of formula (II) is reacted with an acetylene compound of formula (III) to form a compound of formula (IV), and the compound of formula (IV), after optional deprotection, is oxidized to obtain an aldehyde of formula (V), which undergoes isomerisation to the compound of formula (I). The subject of the invention are also novel compounds of formulas (II) and (IV).
A novel one-step diastereo- and enantioselective formation of trans- azetidinones and its application to the total synthesis of cholesterol absorption inhibitors
Wu,Wong,Chen,Ding
, p. 3714 - 3718 (2007/10/03)
An efficient and practical asymmetric process was developed for the synthesis of azetidinone-based cholesterol absorption inhibitors. Key to this synthesis was the discovery of a novel one-step diastereo- and enantioselective formation of trans β-lactams starting from commercially available 3(S)-hydroxy-γ-lactone. Various trans β-lactams can be prepared in good yields and with better than 95:5 enantio- and diastereoselctivity. A Lewis acid-catalyzed aldol condensation and a highly enantioselective oxazaborolidine-catalyzed chiral reduction completes the side chain.