lasalocid benzyl ester                                                                                                                                                              在
                                                                                                                                                                                 
对甲苯磺酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 15.0h,
                                                                                                                以82%的产率得到6-{(E)-(3R,7R)-7-[(2S,3S,5S)-5-Ethyl-5-((2R,5R,6S)-5-ethyl-5-hydroxy-6-methyl-tetrahydro-pyran-2-yl)-3-methyl-tetrahydro-furan-2-yl]-3,5-dimethyl-6-oxo-non-4-enyl}-2-hydroxy-3-methyl-benzoic acid benzyl ester