ChemInform Abstract: Syntheses of Some N‐(Pyrazinecarbonyl) Amino Acids and Peptides.

Abstract

The title compounds and derivatives, e.g. (III), (IV), (VIII), are prepared as shown in the scheme.

Synthesis and Dimethyldioxirane Oxidation of Tetrahydrobenzofurans

“…Thin‐layer chromatography: Merck silica gel 60 F 254 foils with hexane/acetone (7:3, v/v) as eluent. The starting materials 1a − c were synthesized according to known procedures 2. Dimethyldioxirane (as acetone solution) was prepared as described11 and its peroxide content was determined iodometrically.…”

“…2 H ‐Pyran‐2‐ones and fused pyran‐2‐ones are important synthons and building blocks for the synthesis of a variety of organic compounds 1. Since the 5,6,7,8‐tetrahydro‐2 H ‐1‐benzopyran‐2,5‐diones possess several reactive centres, these compounds may be advantageously utilized for various chemical transformations especially with nucleophilic reagents 2. As a usual transformation, these benzopyranones readily react with nitrogen‐containing nucleophiles to afford, e.g.…”