1. Organic Synthesis Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Phayathai Road, Patumwan, Bangkok 10330, Thailand
2. Laboratoire de Synthèse Organique & Méthodologie, ICMMO − CNRS UMR 8182, Université Paris-Sud, 15 rue Georges Clemenceau, 91405 Orsay cedex, France