We report an amino acid salt-catalyzed direct desymmetrization of 3-substituted cyclobutanones through a direct aldol reaction under mild reaction conditions. The developed method provides an array of highly functionalized cyclobutanones bearing three contiguous stereogenic centers in high yields and stereoselectivities with varied functional-group compatibility. Furthermore, the obtained adducts can be smoothly converted into polyfunctional 1,4-butyrolactones with maintained enantioselectivity.
Key words
amino acid salts - desymmetrization - cyclobutanones - asymmetric catalysis - aldol reaction