Cl<sub>3</sub>CCONH<sub>2</sub>/PPh<sub>3</sub>: A Versatile Reagent for Synthesis of Esters
作者:Oraphin Chantarasriwong、Doo Ok Jang、Warinthorn Chavasiri
DOI:10.1080/00397910801979361
日期:2008.8.19
Cl3CCONH(2)/PPh(3) was a versatile reagent to convert carboxylic acids into their corresponding acid chlorides. This intermediate was clearly confirmed by spectroscopic methods (IR, (1)H, (13)C NMR). This one-pot reaction of in situ acid chloride generated with various alcohols successfully furnished the corresponding esters in moderate to excellent yields.
Superbase-Promoted Acylation of Hindered Alcohols
作者:Bosco A. D'S、John G. Verkade
DOI:10.1021/jo951232x
日期:1996.1.1
The commercially available nonionic superbase P(MeNCH(2)CH(2))(3)N (1a) is very useful for the acylation of unreactive hindered alcohols as well as acid-sensitive alcohols. The reactions proceed in high yields using an acid anhydride, and 1a can be regenerated in a single step. The relative rates for benzoylation of (+/-)-menthol in C(6)D(6) using conventional acylation reagents and strong nonionic bases are compared. In general, acetylation with 1a is accelerated in the polar solvent CH(3)CN whereas benzoylation is faster in the nonpolar solvent C(6)H(6). The benzoylation intermediate RC(O)P(MeNCH(2)CH(2))(3)N(+) was found to be in equilibrium with 1a, with lower temperatures favoring the intermediate. The relative stabilities of several known acylating intermediates are compared.