Provided herein are processes for synthesizing intermediates useful in preparing Mcl-1 inhibitors. In particular, provided herein are processes for synthesizing compound D, wherein OPG and R1 are described herein. Compound D can be useful in synthesizing compound A1, or a salt of solvate thereof, and compound A2, or a salt of solvate thereof.
Kikugawa, Yasuo, Journal of the Chemical Society. Perkin transactions I, 1984, # 4, p. 609 - 610