The bio-based methyl coumalate involved Morita–Baylis–Hillman reaction†
We report the first use of renewable, bio-based, non-hazardous feedstock methyl coumalate (MC) in organocatalyzed Morita–Baylis–Hillman (MBH) reactions. This atom-economical pathway employs inexpensive Et3N as a catalyst in ethanol. Synthon MC efficiently constructs C–C bonds with various imines and aldehydes in moderate to good yields. This catalytic process is triggered via an unprecedented 1,6-conjugated addition, as opposed to the classical MBH reaction. Moreover, this methodology expands Morita–Baylis–Hillman donor capabilities to a 2-pyrone derivative for the first time. MBH adducts described herein could be applied to the synthesis of fine chemicals with biologically active structural cores, such as diphenylmethanol, hydroisobenzofurans, and hydroisoindoles.