83510-06-9Relevant articles and documents
Synthesis and preliminary evaluation of dimeric-28-homobrassinosteroids for plant growth regulators
Phutdhawong, Waya S.,Ruensamran, Wanwikar,Phutdhawong, Weerachai
, p. 38 - 44 (2016/11/09)
Preparation of synthetic analogues of 28-homobrassinosteroids is reported. Also, the addition of the 28-homocastasterone at the C6 carbonyl group via allyl Gringard reagent followed by olefin cross metathesis resulted in dimeric analogues. Rice lamina inclination assay showed that the replacement of the C6 carbonyl group by 6α-allyl and 6β hydroxyl groups led to a decrease in bioactivity, whereas the dimeric analogues showed a reduced but significant bioactivity when compared to the 28-homocastasterone.
Improved synthesis of brassinolide
McMorris, Trevor C.,Chavez, Rodrigo G.,Patil, Prakash A.
, p. 295 - 302 (2007/10/03)
Brassinolide has been synthesized from stigmasterol in an overall yield of 7%. The key step in the synthesis is aldol condensation of 2α,3α-isopropylidenedioxy-6-oxo-23,24-dinor-5α-cholan-22-al with 3-isopropylbut-2-enolide carried out at -78°C, which gives a product with 22R,23R stereochemistry in high yield. Catalytic hydrogenation of this product is highly stereoselective leading to the desired 245 stereochemistry in an intermediate which is readily transformed into brassinolide. Copyright 1996 by the Royal Society of Chemistry.
Studies on Steroidal Plant-growth Regulators. Part 29. Osmium Tetroxide-catalysed Asymmetric Dihydroxylation of the (22E,24R)- and the (22E,24S)-24-Alkyl Steroidal Unsaturated Side Chain
Huang, Liang-Fu,Zhou, Wei-Shan,Sun, Li-Qiang,Pan, Xin-Fu
, p. 1683 - 1686 (2007/10/02)
The osmium tetroxide-catalysed asymmetric dihydroxylation of the (22E,24R)- and (22E,24S)-24-methyl steroidal unsaturated side chain with dihydroquinidine p-chlorobenzoate (DHQD) as chiral ligand gave an 8:1 ratio of (22R,23R)- and (22S,23S)-22,23-dihydroxylated products; with a 24-ethyl substituent only a 1.5:1 ratio of (22R,23R)- and (22S,23S)-products was obtained.With the chiral ligand 9-O-(9'-phenanthryl) dihydroquinidine (DHQD-PHN), a 8:1 ratio of (22R,23R)- and (22S,23S)-products was obtained from the (22E,24S)-24-ethyl substituted side chain.