Application of chiral ligands in the key step of synthesis of brassinolides
24-Epibrassinolide and 28-homobrassinolide were synthesized by chiral synthesis of related chiral ligands.In order to determine the chiral ligands using in the key synthesis steps,four kinds of chiral ligands were screened by experiments.The results showed that the chiral ligand DHQD-CLB and DHQD-NAP were suitable for the dihydroxylations of the key steps in 24-epibrassinolide and 28-homobrassinolide synthesis,and the reaction conversion rates reached 79%and 73%,respectively.