PROCESS FOR THE PREPARATION OF TETRONIC ACID DERIVATIVES

摘要

A process for the preparation of tetronic acid derivatives of the general formula: (see fig. I) in which R1 is hydroxyl or phenylamino and R2 is oxo or a group NR1. A 4-haloacetic acid ester is reacted with a base, the resulting tetronic acid intermediate is either diazotized or nitrosylated and the resulting tetronic acid derivative I is optionally reacted further with an amine hydrohalide. The resulting tetronic acid derivatives are important intermediates for the preparation of (+)-biotin, or of pharmaceutical or agricultural active compounds.