Benzoic acid catalyzed aldol-type condensation of aldehydes with ethyldiazoacetate (EDA) under neat conditions at room temperature to afford β-hydroxy-α-diazo carbonyl compounds in good to excellent yields is reported. Furthermore, the condensation of EDA with sugar-derived aldehydes under the same conditions afforded the adducts in excellent yields and high diastereoselectivities.
β-Oxy-α-diazo carbonyl compounds. IV. Reaction with triethyl borane. The influence of the oxy group in the regio- and stereo-controlled alkylation on the diazo carbon
作者:Fidel J. López-Herrera、Francisco Sarabia-García
DOI:10.1016/0040-4039(95)00365-j
日期:1995.4
The reactions of chiral β-oxy-α-diazocarbonyl compounds with triethylborane were studied. The results of the reactions depend on the particular group used to protect the β-hydroxyl function. Thus, hindered protecting groups lead to N-alkylation of the diazocompound. On the other hand, the product with a free hydroxyl group, undergoes C-alkylation in a good yield with full stereoselectivity.