A new and facile preparation of tert-butyl (3R,5S)-6-hydroxy-3,5-O-isopropylidene-3,5-dihydroxyhexanoate
                                
                                    
                                        作者:Fenglai Sun、Gang Xu、Jianping Wu、Lirong Yang                                    
                                    
                                        DOI:10.1016/j.tetasy.2007.09.026
                                    
                                    
                                        日期:2007.10
                                    
                                    A facile method for the preparation of tert-butyl (3R,5S)-6-hydroxy-3,5-O-isopropylidene-3,5-dihydroxyhexanoate is described by a chemoenzymatic approach. In this method, one hydroxyl stereocenter at C5 is obtained with a high ee value (up to 98.0%) via an enzymatic transesterification resolution of 1-chloro-3-(4-methylbenzyloxy)-2-propanol. The other hydroxyl stereocenter at C3 was built with 98.0% de, by acid-hydrolysis of a 1,3-diol-acetonide syn/anti-10. It is noteworthy that the reduction of beta-hydroxy ketone 8 with sodium borohydride can be carried out smoothly in aqueous isopropyl alcohol with a high diastereomeric ratio syn/anti (dr(s:a)) of 4.0:1. (c) 2007 Elsevier Ltd. All rights reserved.