Synthesis of secasterol and 24-episecasterol and their toxicity for MCF-7 cells
摘要:
The convergent synthesis of biosynthetic precursors of brassinosteroids with a Delta(2)-bond in cycle A-secasterol and 24-episecasterol-was performed. The key stages in the construction of the side chain in these compounds were the Julia olefination of the steroid 22-aldehyde followed by the Sharpless asymmetric dihydroxylation of the intermediate Delta(22)-olefin. The cytotoxicity of the synthesized compounds for breast carcinoma MCF-7 cells was assessed.
Studies on steroidal plant growth regulators 22. Osmium tetroxide catalyzed asymmetric dihydroxylation of the (22E, 24R)- and the (22E, 24S)-24-Alkyl steroidal unsaturated side chain
作者:Li-Qiang Sun、Wei-Shan Zhou、Xin-Fu Pan
DOI:10.1016/s0957-4166(00)86139-x
日期:1991.1
The osmium tetroxide catalyzed asymmetric hydroxylation of the (22E, 24R)- and (22E, 24S)-24-alkyl steroidal unsaturated sidechain are described. High stereoselectivity was obtained on dihydroxylation of these unsaturated sidechains, when the 24-alkyl is methyl, while in the case of a 24-ethyl substituent the chiral ligand would be the dihydroquinine p-chlorobenzoate (DHQ).