Synthesis of Chiral alpha,delta-Dioxygenated Allylic Stannanes as Reagents for Carbohydrate Synthesis and Homologation.
Synthesis of Chiral alpha,delta-Dioxygenated Allylic Stannanes as Reagents for Carbohydrate Synthesis and Homologation.
复制标题
手性 α,δ-二氧化烯丙基锡的合成作为碳水化合物合成和同系化的试剂。
DOI：
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发表时间：
1996
影响因子：
3.6
通讯作者：
A. W. Garofalo
中科院分区：
文献类型：
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作者：
J. Marshall;A. W. Garofalo
在γ - otbs巴丁醛4.3c上加入Bu(3)SnLi，然后与TBS-Cl或momm - cl进行醚化反应，得到了δ氧合的烯丙基锡烷4.4和4.5，再与InCl(3)进行转金属反应，并与醛进行原位加成，得到了主要的抗加合物5.1或5.2，并伴有不同数量的同步非对映体。用MOM试剂4.5、ynals 4.3d和4.3e或环己醛4.3a可实现bbb95:5的选择性。当醛为4.3b和4.3c时，反合物和正合物的比例为80:20。还制备了锡烷4.5的S对映体10.1作为碳水化合物合成试剂。因此，在含有InCl(3)的情况下，加入α - odps乙醛10.2会导致加合物10.3作为不可分割的90:10的反和顺非对映体混合物。OTBS衍生物10.4的二羟基化产生了潜在的醛糖前体10.5，产率为81%。
The 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 and ynals 4.3d and 4.3e or cyclohexanecarboxaldehyde 4.3a. With enals 4.3b and 4.3c, 80:20 mixtures of anti and syn adducts are formed. The S enantiomer 10.1 of stannane 4.5 has also been prepared as a reagent for carbohydrate synthesis. Accordingly, addition to alpha-ODPS acetaldehyde 10.2 in the presence of InCl(3) leads to the adduct 10.3 as an inseparable 90:10 mixture of anti and syn diastereomers. Dihydroxylation of the OTBS derivative 10.4 affords the potential altrose precursor 10.5 in 81% yield.