(2R,3R)-(-)-2,3-丁二醇 、
(3,3-Dimethyl-5-oxo-cyclohexyl)-acetaldehyde 在
对甲苯磺酸 作用下,
以
苯 为溶剂,
生成 (2R,3R,9S)-9-((4R,5R)-4,5-Dimethyl-[1,3]dioxolan-2-ylmethyl)-2,3,7,7-tetramethyl-1,4-dioxa-spiro[4.5]decane 、 (2R,3R,9R)-9-((4R,5R)-4,5-Dimethyl-[1,3]dioxolan-2-ylmethyl)-2,3,7,7-tetramethyl-1,4-dioxa-spiro[4.5]decane