to excellent yields with high levels of stereoselectivity. Useful C3-unit elongation, which makes the best use of an allyl ether as a protecting group and a nucleophilic allylation agent, is demonstrated. Mechanisms for the umpolung reaction (of an allyl ether into an allylic anion) and stereoselectivity associated with allylation of aldehydes are discussed.
钯二乙基锌或
钯三乙基
硼烷催化促进环上的2-(烯丙氧基)
四氢呋喃,2-(烯丙氧基)
四氢吡喃及其羟基衍
生物(
核糖,
葡萄糖,
甘露糖,脱氧
核糖,脱氧
葡萄糖)的自烯丙基化。所有反应均在室温下进行,并提供多羟基产物,它们具有均烯丙基醇的结构基序,并具有良好的收率和优异的立体选择性。证明了有用的C3-单元伸长,其充分利用了
烯丙基醚作为保护基和亲核烯丙基化剂。讨论了将
烯丙基醚转化为烯丙基阴离子的烯丙基化反应的机理以及与醛的烯丙基化相关的立体选择性。