ChemInform Abstract: Preparation of Arylpropiolate Esters from Trichlorocyclopropenium Cation and Elaboration of the Esters to Unsymmetrical 1,4-Pentadiyn-3- ones and Unsymmetrical Tellurapyranones.
Abstract
Substitution reaction of the trichlorocyclopropenium salt, obtained from tetrachlorocyclopropene (I), with the aromatic compounds (II) and subsequent ring cleavage with the alcohols (III) produce the arylpropiolate orthoesters (IV) which are hydrolyzed to form the alkyl arylpropiolates (V).
ChemInform Abstract
Substitution reaction of the trichlorocyclopropenium salt, obtained from tetrachlorocyclopropene (I), with the aromatic compounds (II) and subsequent ring cleavage with the alcohols (III) produce the arylpropiolate orthoesters (IV) which are hydrolyzed to form the alkyl arylpropiolates (V). Basic hydrolysis or reduction of (V) with hydride yields the arylpropiolic acids (VI) or the propargyl alcohols (VII). The 4-fluorophenylpropargyl alcohol (VIIa) is transformed into the tellura-4H-pyran-4-one (XIIIa) as outlined in the reaction scheme. The Te- heterocycles (XIIIb) are also prepared.
