A novel nonclassical Wittig reaction of dioxolanones: highly facile and concise enantiospecific synthesis of (3S,4S)-3-hydroxy-4-phenylbutyrolactone
作者:G Vidyasagar Reddy、V Sreevani、D.S Iyengar
DOI:10.1016/s0040-4039(00)02104-3
日期:2001.1
A novel and facile Wittigreaction of dioxolanones is described. An application of this protocol to the stereospecific synthesis in an efficient and practical manner of (3S,4S)-3-hydroxy-4-phenylbutyrolactone is demonstrated.
Sharpless Asymmetric Dihydroxylation on α,β-Unsaturated Diazoketones: A New Entry for the Synthesis of Disubstituted Furanones
作者:Alexánder Talero、Antonio Burtoloso
DOI:10.1055/s-0036-1590977
日期:2017.9
The synthesis of enantiomerically pure 4,5-disubstituted 2-furanones is accomplished in three steps from aldehydes. The steps involve a highly enantioselective Sharpless asymmetric dihydroxylation of α,β-unsaturated diazoketones, followed by a photochemical Wolff rearrangement.
Decarboxylative transformations of paraconicacids, a class of γ-butyrolactones containing a carboxylic acid group at the β-position as their characteristic functionality, by using a combination of AgNO3/K2S2O8 were investigated. The dual function of AgNO3 as an initiator of the decarboxylation process and as a source of nitrogen dioxide radicals that react with aliphatic carboxylic substrates is reported
通过使用AgNO 3 /K 2 S 2 O 8的组合,研究了对康酸(一类在β-位含有羧酸基团作为其特征官能团的γ-丁内酯)的脱羧转化。AgNO 3的双重功能作为脱羧过程的引发剂和作为与脂肪族羧酸底物反应的二氧化氮自由基的来源首次被报道。从仲康酸开始,在一锅操作中以中等的选择性获得了良好的综合收率 (41-85%) 的 β-硝基和 β-羟基 γ-丁内酯。在γ-丁内酯核可耐受的温和条件下,反应在可接受的反应时间(两小时)内完成。本研究提供了对 β-硝基和 β-羟基 γ-丁内酯的直接和位点特异性入口,它们是有机转化中的重要前体。
Asymmetric Oxidative Lactonization of Enynyl Boronates
We present herein the first oxidation of enynylboronates for the synthesis of γ-lactones, including spiro-, and fused-butanolides as well as butenolides that are prevalent in nature products and bioactive molecules. The asymmetric version of this oxidation was also achieved in the presence of chiral ketone and Oxone. This process successively involves the oxidation of C(sp)−B bond, the epoxidation
A general approach to γ-lactones via osmium-catalyzed asymmetric dihydroxylation. Synthesis of (−)- and (+)-muricatacin.
作者:Zhi-Min Wang、Xiu-Lian Zhang、K.Barry Sharpless、Subhash C. Sinha、Anjana Sinha-Bagchi、Ehud Keinan
DOI:10.1016/s0040-4039(00)79001-0
日期:1992.10
γ-lactones have been prepared highly enantioselectively (92–99% ee) using either AD-mix-β or AD-mix-α with both β,γ- and γ,δ-unsaturated esters. The method is exemplified by the three-step synthesis of (−) and (+)-muricatacin in 74% yield and >99% ee.