REACTION OF SULFENE AND DICHLOROKETENE WITH N,N-DISUBSTITUTED 5-AMINOMETHYLENE-1,5,6,7-TETRAHYDRO-2-METHYL-1-PHENYLINDOL-4-ONES. SYNTHESIS OF 1,2-OXATHIINO(6,5-E)INDOLE AND OF PYRANO(2,3-E)INDOLE DERIVATIVES