δ-Oxo acids VI-IX and XIV were converted to δ-thioenol lactones X-XIII and XV on reaction with phosphorus pentasulfide in pyridine. Under these conditions the ε-oxo acid XVI affords B-norsteroids XVII and XVIII. The proposed structures are confirmed by a number of physico-chemical data. The reduction of these thienol lactones with hydrides is also described.
δ-
酮酸 VI-IX 和 XIV 在
吡啶中与五
硫化
磷反应转化为 δ-
硫烯醇内酯 X-XIII 和 XV。在这些条件下,ε-
酮酸 XVI 产生 B-去甾体类
固醇 XVII 和 XVIII。所提出的结构经过多种物理
化学数据确认。这些
硫烯醇内酯的还原也有描述。