5,5-dimethoxy-3-methyl-3Z-penten-1-yne 、 rac-4'β-Ethoxy-1',4',4'a,5',8',8'a-hexahydro-4'aα,6'-dimethylspiro
-5',8'-dion 在
正丁基锂 作用下,
生成 rac-5α-<(E)-5,5-Dimethoxy-3-methylpent-3-en-1-inyl>-4β-ethoxy-4a,8aα-dihydro-5-hydroxy-4aα,6-dimethylspiro-8'(5'H)-on