An effective method for the synthesis of carboxylic esters and lactones using substituted benzoic anhydrides with Lewis acid catalysts
作者:Isamu Shiina
DOI:10.1016/j.tet.2003.12.013
日期:2004.2
benzoic anhydride having electron withdrawing substituent(s) is developed by the promotion of Lewis acidcatalysts. In the presence of a catalytic amount of TiCl2(ClO4)2, various carboxylic esters are prepared in high yields through the formation of the corresponding mixed-anhydrides from 3,5-bis(trifluoromethyl)benzoic anhydride and carboxylic acids. The combined catalyst consisting of TiCl2(ClO4)2 together
A Novel Method for the Preparation of Macrolides from ω-Hydroxycarboxylic Acids
作者:Isamu Shiina、Teruaki Mukaiyama
DOI:10.1246/cl.1994.677
日期:1994.4
An efficient method for the synthesis of macrolides directly from ω-hydroxycarboxylic acids is established by using 4-(trifluoromethyl)benzoic anhydride and a catalytic amount of active titanium(IV) salts together with chlorotrimethylsilane under mild conditions.
A novel and efficient macrolactonization of ω-hydroxycarboxylic acids using 2-methyl-6-nitrobenzoic anhydride (MNBA)
作者:Isamu Shiina、Mari Kubota、Ryoutarou Ibuka
DOI:10.1016/s0040-4039(02)01819-1
日期:2002.10
acids using 2-methyl-6-nitrobenzoic anhydride in the presence of 4-(dimethylamino)pyridine. A similar reaction also occurs with triethylamine when using a catalytic amount of 4-(dimethylamino)pyridine 1-oxide as an effective promoter for the intramolecular condensation reaction. These methods were successfully applied to the synthesis of erythro-aleuritic acid lactone and the efficiency of the cyclizations
BoC<sub>2</sub>O Mediated Macrolactonisation: Syntheses of R-(+)-Ricinoleic Acid Lactone and (±)-12-OH-Stearic Acid Lactone
作者:M. Nagarajan
DOI:10.1080/00397919908086253
日期:1999.7
An efficient chemoenzymatic synthesis of R-(+)-ricinoleic acid lactone and (+/-)-12-OH-stearic acid lactone using Boc(2)O mediated macrolactonisation is reported.
Tin(IV)-catalyzed lactonization of ω-Hydroxy trifluoroethyl esters
作者:James D. White、Neat J. Green、Fraser F. Fleming
DOI:10.1016/s0040-4039(00)73624-0
日期:1993.5
1,1,1-Trifluoroethyl esters of omega-hydroxycarboxylic acids were prepared and their conversion to macrocyclic lactones, including ricinelaidic lactone, was studied in the presence of catalytic quantities of tin(IV) reagents; a mechanism involving exchange of alkoxytrialkyltin species is proposed.