N-protected Methyl Research Articles

ChemInform Abstract: α‐Amino Acid Derived Enaminones and Their Application in the Synthesis of N‐Protected Methyl 5‐Substituted‐4‐hydroxypyrrole‐3‐carboxylates and Other Heterocycles.

AbstractN‐protected α‐amino acids can be converted to enaminones [e.g. compound (III)], which can be isolated, but in many cases easily transform into 4‐hydroxypyrroles and their 4‐oxo‐tautomers [e.g. compounds (IV) and (V)].

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.

ChemInform Abstract: Bakers′ Yeast Reduction of N-Protected Methyl 4-Amino-3-oxobutanoates and 3-Oxopentanoates.

ChemInform Abstract: Bakers′ Yeast Reduction of N-Protected Methyl 4-Amino-3-oxobutanoates and 3-Oxopentanoates.

Solid-phase synthesis of lamellarins Q and O

An efficient solid phase synthesis of the pyrrole-based alkaloids lamellarins Q and O using Merrifield resin and N-protected methyl 3,4-dibromopyrrole-2-carboxylate as a scaffold is described.

Baker's Yeast Reduction ofN-Protected Methyl 4-Amino-3-oxobutanoates and 3-oxopentanoates

Baker's yeast reduction of N-tert-butoxycarbonyl (Boc) or N-benzyloxycarbonyl(Cbz) protected methyl 4-amino-3-oxopentanoates 4b-e and 4-amino-3-oxobutanoates 7a,b stereoselectively afforded the erythro-hydroxy esters 5b-e and (R)-hydroxy esters 8a, b, respectively. The resulting N-protected methyl (R) -4-amino-3-hydroxybutanoate (8) was converted into the biologically active substances, sperabillin C 1c and (R)-GABOB [(R)4-amino-3-hydroxybutanoic acid. 2].