A 1 : 1 mixture of the trisubstituted δ-lactones 11a and 11b was subjected to thermodynamically equilibrated conditions to give predominantly 11b with axial substituents rather than 11a with all equatorial ones, in contrast to the PrelogâDjerassi lactone derivatives 3a and 3b, and, further surprisingly, it has been found that the disubstituted lactone 10 also adopts a chair conformation with axial substituents.
在热力学平衡条件下,三取代δ-内酯 11a 和 11b 的 1 : 1 混合物主要产生具有轴向取代基的 11b,而不是全部具有赤道取代基的 11a,这与 PrelogâDjerassi 内酯衍
生物 3a 和 3b 形成鲜明对比。