Page 1. 240 P. Vermeer et al. Chemistry of acetylenic ethers 105 ... Chemistry of acetylenic ethers 107 Synthesis of 1 ,4-thiaphosphorins and 1,4-thiarsenins M. Schoufs, J. Meijer, P. Vermeer and L. Brandsma Department of Organic Chemistry of the University, Croesestraat 79, Utrecht (Received June 12th, 1974) ... The purity of the compounds, as judged from NMR spectra and GLC was at least 98';/,. J. Meijer, P. Vermwr, HD Verkruijsse and L. Rrundsmu, Recl. ...