N-(p-Methoxybenzyl) groups in some diketopiperazine derivatives were proved to be readily and efficiently removed with ceric ammonium nitrate in acetonitrile-water under mild conditions, where N-benzyl , methoxyl in the aminal structure, and isolated vinyl groups remained unchanged.
The synthesis of two marine natural products containing a 3-alkylidene-6-arylidene-2,5-diketopiperazine scaffold by employing two consecutive aldol condensations starting with 1,4-diacetyl-2,5-diketopiperazine is reported. The target compounds contain a phenol or an imidazole group as aryl substituents, respectively, and suitable conditions for the aldol condensation of 1-acyl-3-alkylidene-2,5-diketopiperazine
Convenient Synthesis of 3-Aminocoumarin Derivatives by the Condensation of 1,4-Diacetyl- or 3-Substituent-2,5-piperazinediones with Various Salicylaldehyde Derivatives
作者:Chung-gi Shin、Yoshiharu Nakajima、Toshiya Haga、Yoshiaki Sato
DOI:10.1246/bcsj.59.3917
日期:1986.12
salicylaldehyde derivatives in the presence of a base, such as potassium t-butoxide or triethylamine, was found to give two extremely different kinds of products: 1-acetyl-3-arylmethylene-PDO and 3-(acylamino)coumarin derivatives. The former, which has a (Z)-geometric structure, was readily converted to the latter by irradiation. Furthermore, the conversion mechanism and the structural confirmation are