Regioselective and reductive cleavage of allyl ethers by NaBH4–HOAc
作者:Zi-Ping Lin、Fung Fuh Wong、Yen-Bo Chen、Chun-Hung Lin、Min-Tsang Hsieh、Jin-Cherng Lien、Yin-Hsuan Chou、Hui-Chang Lin
DOI:10.1016/j.tet.2013.03.020
日期:2013.5
NaBH4 in HOAc led to unexpected reductivecleavage of allyl ether, i.e., the hydrodealkoxylation took place to produce the corresponding 3-deoxy-β-enaminals. In contrast, the reaction of β-enaminals with Zn/HOAc performed H4-elimination to afford a diene product. The result was attributed to the formation of a common eneiminium ion intermediate, and the different reduction reactivity.
Synthesis of Conformationally Constrained <i>C</i>-Glycosyl α- and β-Amino Acids and Sugar−Carbamino Sugar Hybrids via Diels−Alder Reaction
作者:K. Jayakanthan、Yashwant D. Vankar
DOI:10.1021/ol052190u
日期:2005.11.1
[structure: see text] Sugar-derived dienes undergo Diels-Alderreactions with methyl alpha-nitro acrylate and ethyl beta-nitro acrylate to form the corresponding cycloadducts which have been converted into conformationally constrained C-glycosyl alpha- and beta-amino acids. Further, these beta-amino acids are converted into sugar-carbamino sugar hybrid molecules.