Synthesis of Chiral α,δ-Dioxygenated Allylic Stannanes as Reagents for Carbohydrate Synthesis and Homologation
作者:James A. Marshall、Albert W. Garofalo
DOI:10.1021/jo961671b
日期:1996.1.1
delta-oxygenated allylic stannanes 4.4 and 4.5, prepared through addition of Bu(3)SnLi to gamma-OTBS crotonaldehyde 4.3c followed by etherification of the adduct with TBS-Cl or MOM-Cl, undergo transmetalation with InCl(3) and in situ addition to aldehydes leading to mainly anti adducts 5.1 or 5.2, accompanied by varying amounts of syn diastereomers. Selectivities of >95:5 can be realized with the MOM reagent 4.5
通过将Bu(3)SnLi添加到γ-OTBS巴豆醛4.3c中,然后将加合物与TBS-Cl或MOM-Cl醚化制得的δ-加氧烯丙基锡烷4.4和4.5,然后与InCl(3)进行重金属化,然后在在醛中进行原位添加,主要生成抗加合物5.1或5.2,并伴有不同数量的顺式非对映异构体。使用MOM试剂4.5和ynals 4.3d和4.3e或环己烷甲醛4.3a可以实现> 95:5的选择性。用烯醛4.3b和4.3c,形成80∶20的反加合物和顺加合物的混合物。还已经制备了锡烷4.5的S对映体10.1作为碳水化合物合成的试剂。因此,在InCl(3)存在下向α-ODPS乙醛10.2中加成,使加成物10.3成为反对映体和顺式非对映异构体不可分离的90:10混合物。