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