Highly Stereoselective Intramolecular Michael Addition Using α-Sulfinyl Vinyllithium as an Unprecedented Michael Donor
journal contributionposted on 05.12.2000 by Naoyoshi Maezaki, Sachiko Yuyama, Hiroaki Sawamoto, Tomoko Suzuki, Mayuko Izumi, Tetsuaki Tanaka
Any type of content formally published in an academic journal, usually following a peer-review process.
The first example of an asymmetric intramolecular Michael addition reaction using α-lithiated vinylic sulfoxide as a Michael donor is reported. Michael addition of the α-lithiated vinylic sulfoxide to (Z)-enoates proceeds with high diastereoselectivity to give the adducts having a stereogenic center with (R)-configuration at the β-position of the ester in the cyclopentene ring formation. The selectivity was reversed in the six-membered ring formation. On the other hand, the corresponding (E)-enoates provided Michael adducts with poor diastereoselectivity.