Chiral Pool Meets Chiral Catalysis: Eight-Step Convergent Total Synthesis of Anticancer Natural Lipid Mycalol.

An exemplary blend of chiral pool with chiral catalysis is exhibited in an eight-step (longest) convergent asymmetric total synthesis of mycalol, which is a promising anticancer natural lipid from a marine source. The polyhydroxy lipid is constructed by using four blocks, and two of which are derived from the chiral pool (d-mannitol and d-gluconolactone) and the other two by chiral catalysis (Sharpless epoxidation and Keck allylation). Alkylation and metathesis were used to knit the blocks in an excellent display of a modular convergent eight-step synthesis. The modular excess will enable rapid analogue generation as revealed by the convenient synthesis of 4- epi -mycalol similarly in an eight-step sequence.