(i) benzene, (ii) aq. HCl; Multistep reaction;

morpholine; sulfur T=100 - 110°C; 1 h; Title compound not separated from byproducts;

morpholine; sulfur T=100 - 110°C; 1 h; Title compound not separated from byproducts;

toluene-4-sulfonic acid in toluene 4 h; Heating;

1: With lithium boron tetrafluoride; [Ru(2,2′-bipyridine)3][hexafluorophosphate]2; 2,3,5,6-tetramethyl-p-benzoquinone in aceonitrile T=20°C; 5 h; Inert atmosphereIrradiationMolecular sieve; 2: With water; ammonium chloride in acetonitrile T=20°C; 1 h; Inert atmosphereMolecular sieve; optical yield given as percent de;

(i) Et3N, (ii) aq. HCl; Multistep reaction;

morpholine; sulfur T=100 - 110°C; 1 h; Title compound not separated from byproducts;