ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Palladium-catalysed Claisen rearrangement of 6-allyloxypurines

Petr Koukal, Hana Dvořáková, Dalimil Dvořák, and Tomáš Tobrman

Department of Organic Chemistry, Institute of Chemical Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic

E-mail: Tomas.Tobrman@vscht.cz

Abstract: 6-Allyloxypurines readily undergo palladium-catalysed Claisen rearrangement under mild conditions affording N ¹-substituted hypoxanthines. In contrast with the previously reported protocol, the Claisen rearrangement can be performed using Pd(PPh₃)₄ or Pd(dba)₂/dppf in dry THF at 60°C. The reaction can accommodate variously substituted allyl fragments to position N ¹ of the hypoxanthine skeleton with high yields. Retention of the double bond configuration during rearrangement was observed.

Keywords: Claisen rearrangement – purine – allyloxypurines – palladium – hypoxanthine

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0239-y

Chemical Papers 67 (1) 3–8 (2013)