Dearomatizing Cyclization of Arylsulfonylalkoxymethyl Lithiums: A Route to the Podophyllotoxin Skeleton
作者:Jonathan Clayden、Martin N. Kenworthy、Madeleine Helliwell
DOI:10.1021/ol0340585
日期:2003.3.1
[reaction: see text] The phenylsulfonyl group promotes the dearomatizing cyclization of tethered organolithiums onto aromatic rings. With an ether tether, the cyclizations create a new tetrahydrofuran ring, and both cyclization and subsequent electrophilic quenches proceed with high levels of diastereoselectivity. The sulfonyl group can be removed from the cyclized products oxidatively or reductively
[反应:见正文]苯磺酰基可促进束缚有机锂在芳香环上的脱芳环化。使用醚链,环化反应会生成一个新的四氢呋喃环,并且环化反应和随后的亲电猝灭反应都具有很高的非对映选择性。磺酰基可通过氧化或还原从环化产物中除去。萘砜的脱芳香环化反应用于鬼臼毒素的紧密结构类似物的合成。