Methyl-[tetrahydro-pyran-(2Z)-ylidene]-trimethylsilanylmethyl-ammonium 、
丙烯酸甲酯(MA) 在
cesium fluoride 作用下,
生成 (3S,5R)-1-Methyl-6-oxa-1-aza-spiro[4.5]decane-3-carboxylic acid methyl ester 、 (3R,5R)-1-Methyl-6-oxa-1-aza-spiro[4.5]decane-3-carboxylic acid methyl ester