(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