Enantioselective Synthesis of a Key Intermediate in a New Process for Orlistat Using Asymmetric Hydrogenation and a Grignard Reagent Promoted Lactone Cyclization
作者:Mark A. Schwindt、Michael P. Fleming、Yeun-Kwei Han、Lewis M. Hodges、David A. Johnston、Roger P. Micheli、Chris R. Roberts、Roger Snyder、Robert J. Topping、Kurt Püntener、Michelangelo Scalone
DOI:10.1021/op060208q
日期:2007.5.1
A new enantioselective synthesis of Orlistat suitable for large-scale preparation is described. Therein, the first isolated key intermediate (R)-3-hexyl-5,6-dihydro-4-hydroxy-6-undecyl-2H-pyran-2-one (12) is prepared via (a) the asymmetric hydrogenation of methyl 3-oxotetradecanoate to (S)-3-hydroxytetradecanoate (9); (b) the acylation of 9 with 2-bromooctanoyl halide (bromide/chloride) to (R)-3-[
描述了适用于大规模制备的奥利司他的新对映选择性合成。在其中,所述第一分离的关键中间体([R)-3-己基-5,6-二氢-4-羟基-6-十一烷基-2- ħ吡喃-2-酮(12)通过(a)中的不对称氢化制备3-氧代十四烷甲酸甲酯为(S)-3-羟基十四烷酸酯(9);(b)将9用2-溴辛酰基卤化物(溴化物/氯化物)酰化为(R)-3-[(2-溴-1-氧辛基)氧基]-十四烷酸甲酯(11),最后(c)叔丁基氯化镁促进11环化为单一对映体12。先前以对映异构体2的混合物形式发布的单一对映异构体中间体12已通过几个步骤进行到Orlistat(1),而无需进行任何工艺更改。