76236-18-5Relevant academic research and scientific papers
Allylic Chlorination of Gibberellins A3 and A7 Methyl Esters and of Gibberellin A3: Preparation of Gibberellin A5
Bearder, John R.,Kirkwood, Paul S.,MacMillan, Jake
, p. 672 - 678 (2007/10/02)
A high-yield conversion of gibberellin A3 to gibberellin A5 is described.With thionyl chloride, gibberellin A3 methyl ester gives mainly 1β-chlorogibberellin A5 methyl ester; the isomeric 3α-chloro-1-ene was the main product from the reaction with toluene-p-sulphonyl chloride and lithium chloride.Each product is reduced by tri-n-butylstannane and acetylated to give the same mixture of the 13-acetates of gibberellin A5 methyl ester and of the isomeric 1(10)-ene-19,2-lactone.Hydrolysis of gibberellin A5 methyl ester 13-acetate gives gibberellin A5 in 20percent overall yield from gibberellin A3. 2H1>Gibberellin A5 is obtained in the same way by using tri-n-butyl2H1>stannane in the reduction step.Analogous chlorination products of gibberellin A7 methyl ester and of gibberellin A3 are described.
