Organomanganese (II) reagents XX: Manganese mediated Barbier and Reformatsky like reactions an efficient route to homoallylic alcohols and β-acetoxyesters
作者:Gérard Cahiez、Pierre-Yves Chavant
DOI:10.1016/s0040-4039(00)70700-3
日期:1989.1
Allylic halides and α-bromoesters react with manganese metal in ethyl acetate; THF can also be used as solvent if a catalytic amount of zinc chloride is added to the reaction mixture. When the reaction is performed in the presence of various aldehydes or ketones, excellent yields of 1,2-addition products are obtained in preparative conditions.
Enantioselective Carbonyl Allylation, Crotylation, and <i>tert</i>-Prenylation of Furan Methanols and Furfurals via Iridium-Catalyzed Transfer Hydrogenation
作者:Benjamin Bechem、Ryan L. Patman、A. Stephen K. Hashmi、Michael J. Krische
DOI:10.1021/jo902697g
日期:2010.3.5
identical conditions, the corresponding substituted furfurals 2a−c are converted to identical products of allylation, crotylation, and tert-prenylation. Optically enriched products of carbonyl allylation, crotylation, and reverse prenylation 3b, 4b, and 5b were subjected to Achmatowicz rearrangement to furnish the corresponding γ-hydroxy-β-pyrones 6a−c, respectively, with negligible erosion of enantiomeric
5-取代-2-呋喃甲醇1a - c在邻位环金属化铱存在下暴露于乙酸烯丙酯、α-甲基烯丙酯或 1,1-二甲基丙二烯后,会发生对映选择性羰基烯丙基化、巴豆基化和叔异戊二烯化分别由 ( R )-Cl、MeO-BIPHEP、( R )-C3-TUNEPHOS 和 ( R )-C3-SEGPHOS 改性的催化剂。在 2-丙醇存在下,但在其他条件相同的情况下,相应的取代糠醛2a - c被转化为相同的烯丙基化、巴豆化和叔-异戊二烯化。羰基烯丙基化、巴豆化和反向异戊二烯化的光学富集产物3b、4b和5b进行 Achmatowicz 重排,分别提供相应的 γ-羟基-β-吡喃酮6a - c,对映体过量的侵蚀可忽略不计。
Process for preparing cyclopentenolones
申请人:Sumitomo Chemical Company, Limited
公开号:US04398043A1
公开(公告)日:1983-08-09
A process for preparing cyclopentenolones of the formula: ##STR1## wherein R.sub.1 is a straight, branched or cyclic alkyl group having not more than 6 carbon atoms, a straight, branched or cyclic alkenyl group having not more than 6 carbon atoms, a straight or branched alkynyl group having not more than 6 carbon atoms or a group of the formula: ##STR2## wherein R.sub.2 is a hydrogen atom, a methyl group or a halogen atom directly from the corresponding furan-carbinols of the formula: ##STR3## wherein R.sub.1 is as defined above in a single step with an excellent yield, characterized in that the furan-carbinols are treated with water in the presence or absence of a catalyst.
Zinc/Bismuth-Mediated Allylation Reaction of Biomass Feedstocks: Synthesis of Furanic Diols
作者:Mukund P. Sibi、Soumen Biswas、Prakash Kannaboina
DOI:10.1055/a-2241-6966
日期:——
Biomass-based diols have been synthesized by a Zn/Bi-mediated Barbier-type of reaction from furanic aldehydes and allyl halides to access allylated diols. The allylated diols can be readily converted into alkylated diols by hydrogenation. These furanic diols could be potential replacements for fossil fuel based bisphenol A (BPA) which has an adverse endocrine-disrupting effect on humans. This mild
通过锌/铋介导的巴比尔型反应,从呋喃醛和烯丙基卤化物合成基于生物质的二醇,以获得烯丙基化的二醇。烯丙基化的二醇可以通过氢化容易地转化为烷基化的二醇。这些呋喃二醇可能是基于化石燃料的双酚 A (BPA) 的潜在替代品,双酚 A 对人类具有不利的内分泌干扰作用。这种温和且绿色的方案可提供高产率的对称和非对称二醇。烯丙基双键的化学选择性还原为二醇提供了独特的取代。
Wuts, Peter G. M.; Callen, Gary R., Synthetic Communications, 1986, vol. 16, # 14, p. 1833 - 1838