Acetic acid (1S,2S)-2-acetoxy-1-(3-trimethylsilanyl-prop-2-ynyl)-but-3-enyl ester 、 alkaline earth salt of/the/ methylsulfuric acid 生成 Acetic acid (1S,2S,6aR)-2-acetoxy-5-oxo-4-trimethylsilanyl-1,2,3,5,6,6a-hexahydro-pentalen-1-yl ester 、 Acetic acid (1S,2S,6aS)-2-acetoxy-5-oxo-4-trimethylsilanyl-1,2,3,5,6,6a-hexahydro-pentalen-1-yl ester