Mercuric chloride mediated cyclization of tethered alkynedithioacetals has been established as a general route to five- and six-membered carbocycles and heterocycles. Substitution at the alkyne terminus leads to preferential formation of five-membered rings, whereas unsubstituted alkynedithioacetals give six-membered rings as the major products. Mercuric iodide interrupts the reaction at the intermediate dithioacetal
[反应:见正文]
氯化
汞介导的链状炔二
硫缩醛的环化已被确立为通向五元和六元
碳环和杂环的一般途径。在炔基末端的取代导致优先形成五元环,而未取代的炔二
硫缩醛以六元环为主要产物。
碘化汞在中间二
硫缩醛阶段中断反应。