cis-5-carbomethoxy-3-methyl-3-penten-1-yne 、
(2S,3S)-2,3,7,9,9-pentamethyl-1,4-dioxaspiro<4.5>dec-6-en-8-one 在
lithium diisopropyl amide 作用下,
生成
8(Z)-(2S,3S,8S)-8-(5-carbomethoxy-3-methylpent-3-en-1-ynyl)-2,3,7,9,9-pentamethyl-1,4-dioxaspiro<4.5>dec-6-en-8-ol 、 (+)-8(Z)-(2S,3S,8R)-8-(5-carbomethoxy-3-methylpent-3-en-1-ynyl)-2,3,7,9,9-pentamethyl-1,4-dioxaspiro<4.5>dec-6-en-8-ol