37. Synthesis of β-Lactones via Catalytic Asymmetric Heterodimerization of Ketenes
E. Marqués-López, M. Christmann
Simple, but effective: The asymmetric heterodimerization of two different ketenes (see scheme) has been developed 65 years after the first seminal studies on ketene dimerization. The key to sufficiently suppressing the competing homodimerization of the monosubstituted ketene donor (shown in blue) is its slow addition to the disubstituted acceptor (shown in red).