A class of ester–amide oxanorbornadiene (EA-OND) molecules was developed to release alcohol cargos by succinimide formation upon addition of a thiol reagent. The resulting ring-closed adducts undergo further fragmentation by retro-Diels–Alder reaction to release a furan moiety in a manner similar to oxanorbornadiene diesters. The rates of each of these fragmentation pathways in the same medium were found to be sensitive to the steric nature of the amide substituent. Alcohol release was much faster in protic solvents than in aprotic ones, suggesting that this system may be useful for rapid response to thiols in biological environments. Accordingly, the attachment and thiol-dependent release of cholesterol was characterized as an example of the manipulation of a drug-like cargo.

中文翻译：

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使用硫醇敏感的氧杂降冰片二烯连接剂无痕释放酒精

已开发出一类酯-酰胺氧杂降冰片二烯（EA-OND）分子，可在添加硫醇试剂后通过琥珀酰亚胺形成来释放醇货物。最终的闭环加合物通过逆Diels-Alder反应进一步裂解，以类似于氧杂降冰片二烯二酯的方式释放出呋喃部分。发现在相同培养基中每个这些断裂途径的速率对酰胺取代基的空间性质敏感。质子传递溶剂中的乙醇释放比非质子传递溶剂快得多，这表明该系统对于生物环境中对硫醇的快速响应可能有用。因此，胆固醇的附着和硫醇依赖性释放被表征为操纵类似药物的货物的一个实例。