Thiacycloheptadeca-3,8,10,15-tetrayne and thiacycloheptadeca-2,8,10,16-tetrayne-4,15-diol. Attempted synthesis of thiaannulene
Cyclisation of di(octa-2,7-diynyl) sulphide by oxidation under Glaser conditions afforded thiacycloheptadeca-3,8,10,15-tetrayne, but attempted prototropic rearrangement of this compound to thiaannulene led to a complex mixture of products. Reaction of bis-sodioethynyl sulphide with hex-5-ynal gave bis-(3-hydroxyocta-1,7-diynyl) sulphide, which on Glaser cyclisation yielded thiacycloheptadeca-2,8,10,16-tetrayne-4,15-diol. The latter compound also gave a mixture on treatment with base or acid.