This paper summarizes the reaction of DABCO with the enol tosylate derivatives made from (L-Ser-L-Ser) and (L-Phe-L-Ser) diketopiperazines (DKP’s). The reaction between DABCO and EE-di-tosylate (L-Ser-L-Ser) DKP (2), results in the isomerization of the serine di-tosylate from EE-2 to ZZ-2. | Feasibility study on the reaction of 1 4-diazabicyclo octane DABCO with L-Serine-L-Serine and L-Phenylalanine-L-Serine diketopiperazines Current Chemistry Letters 5 2016 155 164 Contents lists available at GrowingScience Current Chemistry Letters homepage Feasibility study on the reaction of 1 4-diazabicyclo octane DABCO with L-Serine-L-Serine and L-Phenylalanine-L-Serine diketopiperazines Sitaram Bhavaraju 51 Lower College Road Dept. of Chemistry University of Rhode Island Kingston RI-02881 USA CHRONICLE ABSTRACT Article history This paper summarizes the reaction of DABCO with the enol tosylate derivatives made from Received January 21 2016 L-Ser-L-Ser and L-Phe-L-Ser diketopiperazines DKP s . The reaction between DABCO Received in revised form and EE-di-tosylate L-Ser-L-Ser DKP 2 results in the isomerization of the serine di-tosylate July 10 2016 from EE-2 to ZZ-2. This is the first direct example of the utility of DABCO as a reagent Accepted 13 July 2016 demonstrating the successful isomerization in a DKP derivative. The E-enol tosylate of L- Available online Phe-L-Ser DKP 4 upon reaction with DABCO provided a unique bis-ylidiene product 5 . 13 July 2016 Keywords 2 5-Diketopiperazine DKP Isomerization 1 4- diazabicyclo octane DABCO Enol tosylate Bis-Ylidiene 2016 Growing Science Ltd. All rights reserved. 1. Introduction 2 5-diketopiperazines DKP s such as compounds 1 and 3 have potential to serve as building blocks for important class of The presence of these 2 5-DKP s in bioactive natural products their synthetic utility and applications in medicinal chemistry is excellently reviewed by A detailed description of the application of these 2 5-DKP s in peptide and combinatorial chemistry is thoroughly reviewed by . 2 5-DKP s have continued to establish impact on the frontiers of organic structural and medicinal DKP derivatives such as enol di-tosylate 2 and enol .
