Diastereoselective synthesis of 3-amino-2-hydroxyalkanoic acid derivatives
摘要:
Both diastereomers of 3-amino-2-hydroxyalkanoic acid derivatives were synthesized selectively by LDA-induced reaction of N-methoxycarbonyl-1-methoxyamines with O-protected N,N-dimethylglycolamides. The inversion of the diastereoselectivity was highly achieved by 1) selecting the O-protecting groups and 2) the addition of Ti(OPr-i)(4).
The diastereoselectivity of the addition of enolateanions of ketones or esters to N-Methoxycarbonylimines generated in situ from α-Methoxy carbamates was studied.
Preparation of Acyclic<i>N</i>-Acyl-<i>N</i>,<i>O</i>-acetals by Decarboxylation of<i>N</i>-Protected α-Amino Acids and Studies of Asymmetric Amidoalkylation with Trimethylsilyl Cyanide
作者:Kenn E. Harding、Lee T. Liu、David G. Farrar、M. Todd Coleman、Susan K. Tansey
DOI:10.1080/00397919108021290
日期:1991.6
Abstract Oxidative decarboxylation of N-acyl-α-amino acids with lead tetra-acetate followed by treatment with methanol provides a facile method for preparation of acyclic N-acyl-N,O-acetals, which can be used in asymmetric α-amidoalkylation reactions using trimethylsilyl cyanide as nucleophile.
The reaction of N-acyl-alpha-methoxyamines with allyl-, propargyl-, and benzylzinc bromides and Reformatsky reagents proceeds in THF at room temperature. Homoallyl- and homopropargylamines and beta-amino esters are synthesized in good yields.
376. The constitution of ascorbic acid. Action of sodium hypochlorite on α-methoxy-acid amides