180922-45-6

Upstream product

• 7367-88-6 ethyl (E)-2-decenate 
• 154701-92-5 (2S,3S)-ethyl 2-hydroxy-3-(N-tosylamino)-4-iodobutyrate 
• 154701-91-4 (2S,3R)-2-hydroxy-3-(tosylamino)butano-4-lactone 
• 147228-21-5 (S)-4-<(tolylsulfonyl)amino>-γ-butyrolactone 
• 185015-84-3 (4R,5S)-4-Heptyl-2-oxo-3-(toluene-4-sulfonyl)-oxazolidine-5-carboxylic acid (1S,2R)-2-phenyl-cyclohexyl ester 
• 124-13-0 Octanal 
• 201798-57-4 (2S,3R)-2-Hydroxy-3-(toluene-4-sulfonylamino)-decanoic acid methyl ester 
• 180922-43-4 ethyl (2S,3R)-2-hydroxy-3-(tosylamino)decanoate 

Relevant academic research and scientific papers

A short and enantioselective synthesis of N-terminal components of bestatin, amastatin and microginin

Synthesis of the N-terminal components of bestatin, amastatin and microginin has been achieved using Sharpless asymmetric aminohydroxylation reaction as key step.

Enantiospecific and diastereoselective synthesis of syn-β-amino-α-hydroxy acids

The reaction of chiral α-hydroxy β,γ-unsaturated esters with tosyl isocyanate followed by cyclization of the resulting allylic carbamates with iodine in the presence of sodium carbonate provided trans-4,5-disubstituted 2-oxazolidinone derivatives in a highly diastereoselective manner. The subsequent removal of the iodo group and the protective functionality afforded the syn-β-amino-α-hydroxy acids. Using the reaction sequence, (2R,3S)- and (2S,3R)-3-amino-2-hydroxy acids were synthesized with high enantioselectivity.

104. The enantioselective synthesis of β-amino acids, their α-hydroxy derivatives, and the N-terminal components of bestatin and microginin

L-Aspartic acid by tosylation, anhydride formation, and reduction with NaBH4 was converted into (3S)-3-(tosylamino)butan-4-olide (8; Scheme 1). Treatment of 8 with ethanolic trimethylsilyl iodide gave the N-protected deoxy-iodo-β-homoserine ethyl ester 9. The latter, on successive nucleophilic displacement with lithium dialkylcuprates (→ 10a-e), alkaline hydrolysis (→ 11a-e), and reductive removal of the tosyl group, produced the corresponding 4-substituted (3R)-3-aminobutanoic acids 12a-e (ee >99%). Electrophilic hydroxylation of 8 (→ 19; Scheme 3), subsequent iodo-esterification (→ 21; Scheme 4), and nucleophilic alkylation and phenylation afforded, after saponification and deprotection, a series of 4-substituted (2S,3A)-3-amino-2-hydroxybutanoic acids 24 including the N-terminal acids 24e (= 3) and 24f (= 4) of bestatin and microginin (de >95%), respectively.