188434-22-2

Upstream product

• 98-59-9 p-toluenesulfonyl chloride 
• 188434-15-3 ent-13-Acetoxy-3β-hydroxy-20-norgibberella-1(10),16-diene-7,19-dioic acid 7,19-dimethyl ester 
• 188434-23-3 ent-13-Acetoxy-3β-trifluoromethylsulfonyloxy-20-norgibberella-1(10),16-diene-7,19-dioic acid 7,19-dimethyl ester 
• 188434-13-1 ent-13-Acetoxy-3-oxo-20-norgibberella-1⁽¹⁰⁾,16-diene-7,19-dioic acid 7,19-dimethyl ester 

Relevant academic research and scientific papers

Unusual reactions of methylsulfonyl esters: Syntheses of 3α-methyl and 3β-methyl gibberellin A20

Gibberellin A3 has been converted to 3α-methylGA20 8 in 33% yield via catalytic hydrogenation of the 3-exo-methylene derivative 14. In an attempt to prepare 3β-methylGA20 9, the 3α-methanesulfonate 25 has been treated with lithium dimethylcuprate; only the β-keto sultones 26 and 27 have been isolated (84% yield). In contrast, under similar conditions the 3α-methanesulfonate 35 gave the 2-oxopropylsulfonyloxy derivatives 36 and 37. Synthesis of 3β-methylGA20 has been achieved via reaction of the 3α-trifluoromethane-sulfonate 38 with lithium dimethylcuprate. 3α-MethylGA20 and 3β-methylGA20 show similar activity to GA20 (and significantly less activity than GA3) in the stimulation of stem elongation of dwarf rice seedlings.