The first efficient asymmetric synthesis of obolactone 1 has been accomplished in 11 steps and with a 15% overall yield in which Brown's enantioselective allylation reactions and ring-closing metathesis reaction are key steps.

中文翻译：

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简明不对称全合成内酯

olactactone 1的第一个有效的不对称合成已经完成了11个步骤，总收率为15％，其中Brown的对映选择性烯丙基化反应和闭环复分解反应是关键步骤。