Chemoselective conjugate addition of dimethylzinc-mediated ether and acetal radicals to alkylidenemalonates and asymmetric reactions.
Cyclic and acyclic ether or acetal radicals were generated directly from ethers or acetals by the action of dimethylzinc-air, and their subsequent conjugate addition reaction with alkylidenemalonates afforded the corresponding conjugate adducts in reasonably high yields. The reaction with benzylidenemalonates bearing formyl and imino groups gave chemoselectively the conjugate addition products. The asymmetric reaction of bis(8-phenylmenthyl) benzylidenemalonate proceeded diastereoselectively to provide the adduct with 93:7 dr.
Yamada
Ken-ichi
K
Graduate School of Pharmaceutical Sciences, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
Maekawa
Masaru
M
Akindele
Tito
T
Nakano
Mayu
M
Yamamoto
Yasutomo
Y
Tomioka
Kiyoshi
K
D000080:Acetals / Q000737:chemistry*; D003460:Crystallization; D004987:Ethers / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D008314:Malonates / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism
D000080:Acetals; D004987:Ethers; D005609:Free Radicals; D007202:Indicators and Reagents; D008314:Malonates; D009942:Organometallic Compounds; C511262:dimethylzinc