A Safe, Convenient and Efficient One-Pot Synthesis of α-Chloroketone Acetals Directly from Ketones Using Iodobenzene Dichloride
作者:Chi Zhang、Jun Yu
DOI:10.1055/s-0029-1216856
日期:2009.7
aliphatic and aromatic ketones, can be directly converted into their corresponding α-chloroketone acetals in high to excellent yields using iodobenzenedichloride in ethylene glycol in the presence of 4 Å molecular sieves at room temperature. ketones - iodobenzene - dichloride - halogenation - hypervalent iodine - acetals
PROCESS FOR PRODUCTION OF OPTICALLY ACTIVE COMPOUND
申请人:Ishii Yutaka
公开号:US20110288315A1
公开(公告)日:2011-11-24
A 2-aryl-2-halomethyl-4-chloromethyl-1,3-dioxolane (A) can be produced conveniently without decreasing its optical purity by reacting an optically active monochlorohydrin and an aryl (halomethyl) ketone (starting materials) with each other in the presence of an acid catalyst. From the optically active compound (A) thus produced, an optically active carboxylic acid (2-aryl-2-halomethyl-1,3-dioxolan-4-yl)methyl ester and an optically active sulfonic acid (2-aryl-2-halomethyl-1,3-dioxolan-4-yl)methyl ester (both of which are useful intermediates for the production of ketoconazole) can be produced with good efficiency. An optically active trans-carboxylic acid (2-aryl-2-halomethyl-1,3-dioxolan-4-yl)methyl ester can be isomerized into its cis-form in the presence of an acid catalyst.
One-step for the preparation of α-haloacetal of ketones with N-bromosuccinimide/N-chlorosuccinimide (NBS/NCS) and ethylene glycol
A new process that could directly prepare α-haloacetal of ketones from various ketones with N-halosuccinimide (NBS/NCS) and ethylene glycol in one step without any other catalysts was reported. The effects of solvents, NBS/NCS and reaction temperature were investigated. Under the optimal condition, most of α-haloacetals of ketones were obtained in 90–100% yield.