183584-65-8Relevant academic research and scientific papers
Intramolecular nucleophilic acyl substitution reaction of 3,4-alkadienyl carbonates mediated by Ti(O-i-Pr)4/2 i-PrMgCl reagent. Efficient synthesis of optically active β,γ-unsaturated esters with an α-substituent
Yoshida, Yukio,Okamoto, Sentaro,Sato, Fumie
, p. 7826 - 7831 (2007/10/03)
Treatment of 3,4-alkadienyl carbonates 2a-i with a low-valent titanium reagent diisopropoxy(η2-propene)titanium (1), readily generated by the reaction of Ti(O-i-Pr)4 with 2 i-PrMgCl, resulted in an intramolecular nucleophilic acyl substitution (INAS) reaction to afford vinyltitanium compounds 3 which, in turn, reacted with H3O+, D2O, or iodine to give α-substituted β,γ-unsaturated esters 4 in good to excellent yields. The olefin moiety of the hydrolysis product 4 has (Z)-geometry mainly except for 4h. Starting from chiral 2f or 2g, the reaction proceeded stereospecifically to give optically active α-substituted β,γ-unsaturated ester 4f or 4g having (Z)-olefin geometry exclusively.
