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

Substituted homoallenyl aldehydes and their derivatives. Part 1: Homoallenyl aldehydes and protected hydrazones

Juraj Galeta, Stanislav Man, and Milan Potáček

Department of Chemistry, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic

E-mail: potacek@chemi.muni.cz

Abstract: The paper presents a simple synthesis of substituted propargyl vinyl ethers and their subsequent thermally-initiated Claisen rearrangement leading to various 3-substituted homoallenyl aldehydes. Several methods, including Sonogashira coupling, base-promoted substitution on the triple bond by sodium amide or butyllithium, and the preparation of substituted propargyl alcohols, were used in the initial step. Phosphate-protected homoallenyl aldehyde hydrazone derivatives were synthesised and fully characterised. The stereochemistry of 9-anthracene carbaldehyde hydrazone, which, surprisingly, afforded both cis and trans isomers, was established using X-ray analysis.

Keywords: homoallenyl aldehyde – hydrazone – Claisen rearrangement, isomerisation

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-012-0215-6

Chemical Papers 67 (1) 29–39 (2013)