Erratum to: Phospho sulfonic acid as efficient heterogeneous Brønsted acidic catalyst for one-pot synthesis of 14H-dibenzo[a,j]xanthenes and 1,8-dioxo-octahydro-xanthenes

Corrigendum to: Chemical Papers 69(4):536–543 (2015) DOI 10.1515/chempap-2015-0058

We would like to amend the information that appeared in our paper on page 537. The statement that “The present work reports a new and simple method for the synthesis of aryl-14H-dibenzo[a,j]xanthenes IIIa–IIIn and 1,8-dioxo-octahydro-xanthene V using phospho sulfonic acid as a new, environmentally benign, heterogeneous, solid acid catalyst under solvent-free conditions” is incorrect. The use of phospho sulfuric acid as a catalyst for this reaction was studied concurrently by another group (Kiasat et al. 2013) and their results were published prior to the publication of our paper: Editors thank Prof. Saghanezhad (Shahid Chamran University, Ahvaz, Iran) for bringing this oversight to our attention and apologize to him and readers for the incorrect declaration of the priority.