Synergistic Catalysis: Enantioselective Ring Expansion of Vinyl Cyclopropanes Combining Four Catalytic Cycles for the Synthesis of Highly Substituted Spirocyclopentanes Bearing up to Four Stereocenters
作者:Marta Meazza、Ramon Rios
DOI:10.1002/chem.201601893
日期:2016.7.11
A double synergistic cascade reaction is reported, combining transition metal and amine catalysis. The reaction between vinyl cyclopropanes and enals renders the final cyclopentane derivatives in excellent yields and stereoselectivities.
Stereoselective Preparation of Dienol Phosphates from α,β-Ethylenic Aldehydes
作者:Gérard Cahiez、Vanessa Habiak、Olivier Gager
DOI:10.1021/jo800865z
日期:2008.9.1
The first stereoselective method of preparation of (E)-dienol phosphates fromalpha,beta-ethylenic aldehydes is described. The key point is the stereoselective enolization of conjugated alkenals by potassium tert-butoxide in the presence of N-methylpyrrolidinone (NMP).
A new fluorescent lactose molecule (pyd-lact) (E)-1-(galactose-β-(1→4)-β-d-glucopyranosyl)-4-(1-pyrene)-but-3-en-2-one, has been synthesized by attaching 1-pyrene-but-3-ene-2-one to lactose.
in-situ-generated acylnitrosodienophiles 5a and 5b, leading thereby to the corresponding dihydrooxazines 7a–d and 8c–d. cis-Glycolization of these latter adducts stereospecifically gave the dihydro derivatives 9a–d and 10d which, after sequential hydrogenolysis, deacetalization, and instant cyclization, led to the aminodeoxyribose derivatives 17a, 17f, and 18, and to the amino-dideoxyallose compounds 17c
Terminal Conjugated Trienal Acetal Compound and Method for Producing Terminal Conjugated Trienal Compound Using the Same
申请人:Shin-Etsu Chemical Co., Ltd.
公开号:US20170253548A1
公开(公告)日:2017-09-07
Provided are a terminal conjugated trienal acetal compound useful as an intermediate for producing a terminal conjugated trienal compound, and a method for producing a terminal conjugated trienal compound through deprotection of the terminal conjugated trienal acetal compound. More specifically, provided are a terminal conjugated trienal acetal compound represented by General Formula (1); a method for producing a (Z,E)-terminal conjugated trienal acetal compound, the method comprising the step of: reacting a phosphonium salt represented by General Formula (7) with (E)-2,4-pentadienal through Wittig reaction to obtain a (Z,E)-terminal conjugated trienal acetal compound represented by General Formula (3); and a method for producing a terminal conjugated trienal compound, the method comprising the step of: deprotecting the terminal conjugated trienal acetal compound represented by General Formula (1) to obtain a terminal conjugated trienal compound represented by General Formula (2).