SYNTHESIS OF BIS(1-PHENOXY-PROPEN-2-YL)-S ULFANES DERIVED FROM BIS(L-CHLORO-3-PHENOXY-PROP-2-YL)-SULFANES WITH POTASSIUM-TERT.-BUTOXID - DETERMINATION OF THE E,E-CONFIGURATION

Bis(1-chloro-3-phenoxy-prop-2-yl)-sulfanes (1), anti-MARKOVNIKOV 2:1-a dducts of allylphenyl ethers with sulfur dichloride at low temperature are transformed in the presence of potassium-tert.-butoxid by dehydro halogenation / prototropic rearrangement to phenoxyvinyl sulfanes, the E,E-bis(1-phenoxy-propen-2-yl)sulfanes 3. Sulfanes 3 are of special i nterest as a model for unsaturated macrocycles B derivated from dithia crown ethers A. The configuration was assigned using H-1-n.m.r.- and C -13-n.m.r.-spectroscopy. The molecular structure was determinded by X- ray diffraction techniques. Rearrangement of sulfur-substituted allyl ethers 2 to the propenyl isomers 3a proceeds in a stereospecific manne r as for common allyl ethers described in the literature.