190517-06-7

Upstream product

• 190517-05-6 r-3,c-7-dibenzoyloxy-c-5-hydroxycycloheptene 
• 74-88-4 methyl iodide 
• 98-88-4 benzoyl chloride 
• 190517-03-4 (1R,4S,6R)-6-(tert-Butyl-diphenyl-silanyloxy)-cyclohept-2-ene-1,4-diol 
• 190517-04-5 r-3,c-7-dibenzoyloxy-c-5-(tert-butyldiphenylsilyl)oxycycloheptene 
• 190517-01-2 tert-Butyl-[(1R,3R,5S)-(6,7-dioxa-bicyclo[3.2.2]non-8-en-3-yl)oxy]-diphenyl-silane 

Relevant academic research and scientific papers

Palladium-mediated asymmetric synthesis of 3β,5β,7β-trihydroxycycloheptene derivatives

Asymmetric alkylation of 3,5,7-trihydroxycycloheptene derivative 15 was developed using a palladium catalyst with chiral ligand. The reaction site of π-allylpalladium complex 18 is controlled by steric repulsion between the nuclcophile and the substituents on the cycloheptene ring. When 15b was reacted with lithium dimethyl malonate using a catalytic amount of [Pd(C3H5)Cl]2 in the presence of (S)-BINAPO in THF, alkylated product 17 was obtained in 71% yield with 42% ee. However, the reaction of 15b with a large nucleophile, diethyl 2-lithio-2-(2-propenyl)malonate, in the presence of [Pd(C3H5)Cl]2 and (S)-BINAP in THF gave alkylated product 21d in 41% yield with 94% ee. In a similar manner, the reaction of 15b with dimethyl 2-(3-butenyl)-2-lithiomalonate 5e gave 21e in 64% yield with 82% ee.