Naphthalene-catalysed lithiation of carbamoyl and thiocarbamoyl chlorides under Barbier-type reaction conditions
作者:Diego J. Ramón、Miguel Yus
DOI:10.1016/0040-4020(96)00827-7
日期:1996.10
The reaction of different carbamoyl or thiocarbamoyl chlorides 1 with carbonyl compounds or imines 2 in the presence of an excess of lithium powder and a catalytic amount of naphthalene (3 mol %) in THF at −78°C leads, after hydrolysis with water, to the expected α-hydroxy or α-amino amides 3, respectively. In the case of allylic or benzylic derivatives 1a,c, when longer reaction times are used, the
Stereoselective Synthesis of .BETA.-Hydroxyphenylalanines Using Imino 1,2-Wittig Rearrangement of Hydroximates
作者:Okiko Miyata、Hiroshi Asai、Takeaki Naito
DOI:10.1248/cpb.53.355
日期:——
beta-hydroxy-alpha-amino acids. Upon treatment with LDA, hydroximates smoothly underwent the rearrangement to give Z-2-hydroxyoxime ethers in good yield, which were converted into both cis- and trans-oxazolidinones with high stereoselectivity. The cis- and trans-oxazolidinones were stereoselectively converted into erythro- and threo-beta-hydroxyphenylalanines, respectively, via the oxidative cleavage of a furan
Direct Formation of the Carbonyl Anion of Diisopropyl Formamide
作者:Robert R. Fraser、Patrick R. Hubert
DOI:10.1139/v74-029
日期:1974.1.1
the carbonyl anion, LiCON[CH(CH3)2]2. Reactions of this anion with benzaldehyde, benzophenone, ethyl benzoate, acetone, and propionaldehyde occur in yields ranging from 30–92%. Thus, this anion provides a useful method for the synthesis of α-hydroxy and α-keto acids, particularly in cases where cyanohydrin formation is difficult.
Direct formation, and reactions of a carbonyl anion free from competitive nucleophiles
作者:Keith Smith、Kalyanaraman Swaminathan
DOI:10.1039/c39760000387
日期:——
At low temperature, in tetrahydrofuran (THF)–ether-pentane, ButLi abstracts a proton from bis(isopropyl)formamide to give LiCONPri2, which reacts with carbonyl compounds to give high yields of α-hydroxyamides.
在低温下,Bu t Li在四氢呋喃(THF)-醚-戊烷中从双(异丙基)甲酰胺中提取出一个质子,生成LiCONPr i 2,LiCONPr i 2与羰基化合物反应生成高产率的α-羟基酰胺。
Toda, Fumio; Tanaka, Koichi; Tange, Hiroshi, Journal of the Chemical Society. Perkin transactions I, 1989, p. 1555 - 1556