A synthesis of allahabadolactone A is described employing diastereoselective Diels–Alder and selenocyclization reactions, starting from (R)-citronellal and propylene oxide. The Diels–Alder substrate is built up in an efficient manner by rhodium-catalyzed alkyne hydroboration and palladium-catalyzed coupling reactions of E-1,2-dichloroethene. It is observed that the Diels–Alder reaction only displays high diastereoselectivity when the diene bears an additional alkene substituent but not an alkyne substituent.

中文翻译：

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阿拉哈巴内酯A的合成

描述了采用非对映选择性Diels-Alder和硒环化反应（从（R）-香茅醛和环氧丙烷开始）合成阿拉巴巴内酯A的方法。Diels–Alder底物通过铑催化的炔烃硼氢化反应和钯催化的E -1,2-二氯乙烯偶联反应而高效地构建。可以观察到，当二烯带有一个额外的烯烃取代基而不是一个炔烃取代基时，狄尔斯-阿尔德反应仅表现出高的非对映选择性。