57003-46-0Relevant academic research and scientific papers
Carbon-Carbon Bond Formation at the γ-Position of Dienolates via the Germanium Masked Dienolates
Yamamoto, Yoshinori,Hatsuya, Satoshi,Yamada, Jun-ichi
, p. 1639 - 1640 (2007/10/02)
Trapping of the lithium dienolate (1), derived from 3-methyl-2-butenoate, with Me3GeX (X = Br or Cl gives the α-germylated derivative (2), which reacts with various electrophiles at the γ-position.
Diastereo- and Regio-selective Aldol Condensation by Trapping Dienolates with Tin
Yamamoto, Yoshinori,Hatsuya, Satoshi,Yamada, Jun-ichi
, p. 561 - 562 (2007/10/02)
Although the reaction of dienolate (1) with aldehydes is frequently lacking in regio- and diastereo-selectivity, the γ-tin substituted derivatives (5), easily obtainable from (1), give (3) and (4) diastereoselectively by controlling the reaction conditions.
Selective γ-Substitution of α,β-Unsaturated Esters via α-Trimethylsilyl β,γ-Unsaturated Esters
Albaugh-Robertson, Pamela,Katzenellenbogen, John A.
, p. 5288 - 5302 (2007/10/02)
In order to achieve selective γ-substitution of α,β-unsaturated esters, we investigated the directive effect of silicon in the reaction of various electrophiles with α-trimethylsilyl β,γ-unsaturated esters.These esters were prepared by nickel-catalyzed vinylation reactions of the lithium enolate of ethyl α-(trimethylsilyl)acetate.The α-silyl β,γ-unsaturated esters reacted with a variety of electrophiles (aldehydes, ketones, acetals, ketals, acid chlorides, and chloro thioethers) in the presence of Lewis acids (titanium tetrachloride and trimethylsilyl trifluoromethanesulfonate) to give exclusively the γ-substituted product in moderate to good yields.In some cases, the primary substitution products underwent additional conversions under the reaction conditions, such as the cyclization of the δ-hydroxyl or δ-keto enoates to dihydropyrones or pyrones, respectively.These α-silyl β,γ-unsaturated esters are effective reagents for achieving complete γ-selective substitution of α,β-unsaturated ester systems.
