酸素, 硫黄を含む異項環化合物の液体アンモニア中アルカリ金属による開裂反応

抄録

Examination was made on the cleavage reaction of dibenzofuran (II), phenoxathiin (III), thianthrene (IV), and 2, 7-dimethylthianthrene (V) with alkali metal in liquid ammonia and results thereby obtained are listed in Table I. The ether linkage in dibenzofuran (II) is comparatively difficult to be cleaved and reduction of the ring takes place preferably when ammonium chloride is added. In phenoxathiin (III), the sulfur linkage is cleaved first to form o-phenoxybenzenethiol and a mercapto group is newly formed in the ortho-position, making it difficult for subsequent cleavage of the ether linkage, as in the case of 2-hydroxydiphenyl ether. In the case of thianthrene (IV) and dimethylthianthrene (V), however, the two sulfur linkages are easily cleaved, forming two moles of thiophenol.