By substituting thiourea for urea the reaction was favored by decreased temperatures (30- 35') and smaller excesses of sodium ethoxide. The molar ratios of sodium, thiourea and lactone were 2: la5: 1, respectively. The intermediate lactone thioureide (I) was isolated and identified in two cases. During the purification of the n-butyl and isoamyl derivatives these compounds were recovered from the more soluble fractions. Of the eight thiobarbituric ...
