204511-99-9

Upstream product

• 148432-25-1 (S,S)-(+)-1-[3-Hydroxy-1-(2,6-di-tert-butyl-4-methoxy-1-phenoxycarbonyl)-3-phenyl-1-propylideneamino]-2-(1-ethyl-1-methoxypropyl)pyrrolidine 
• 118535-62-9 (S)-(-)-1-amino-2-(1'-methoxy-1'-ethylpropyl)pyrrolidine 
• 148432-21-7 (S)-(+)-1-[1-(2,6-Di-tert-butyl-4-methoxy-1-phenoxycarbonyl)-1-ethylideneamino]-2-(1-methoxy-1-ethylpropyl)pyrrolidine 

Downstream Products

• 883723-47-5 2-acetoxy-4-phenylbutanoic acid 
• 235765-45-4 (S)-(-)-3-acetoxy-5-phenyl-2(5H)-furanone 
• 746639-75-8 (S)-3-hydroxy-5-phenylfuran-2(5H)-one 

Relevant academic research and scientific papers

Diastereo- and enantioselective synthesis of 4- and 3,4-substituted 2- acetoxy-butyrolactones

An efficient asymmetric synthesis of 4-mono-and 3,4-disubstituted 2- acetoxy-butyrolactones 2 has been developed, based on a hydrazone-mediated asymmetric aldol reaction, an intramolecular lactonization and a stereoselective hydrogenation of the resulting butenolides 1. An application of this process in the synthesis of the natural hunger substance 3 (ee = 90%) is also presented.

Enantioselective synthesis of protected isotetronic acids

Isotetronic acids are subunits of a number of natural products. They are of interest in agricultural and pharmaceutical research and are important synthetic intermediates. This paper describes the first highly diastereo- and enantioselective synthesis of isotetronic acids in 4 to 5 steps (de, ee > 98%). Key steps in the reaction sequence are the diastereoselective aldol reaction of the 2-oxoesters 5 as their SAEP hydrazones (S)-6 with aldehydes, followed by base-promoted lactonization to the hydrazonolactones 8. Subsequent oxidative cleavage of the hydrazone moiety afforded the enantiomerically pure O-protected isotetronic acids (R)-/(S)-9.