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Synthon

According to Corey, synthon is defined as structural units within a molecule that are related to possible synthetic operations.20 Some people recently regard a synthon as a synonym of a building block. This is different from Corey s original usage. [Pg.6]

Retrosynthetic analysis is the basic operation in planning organic synthesis. Knowledge on synthetic reactions and insight to determine a useful reaction are of basic importance in planning synthesis. The higher the number of synthons in a target molecule, the more difficult it is to synthesize. Corey emphasizes in depth the importance of retrosynthetic analysis.21 [Pg.6]


Figure lO.J-31. Disconnection of the strategic bond yields (charged) synthons. The synthons are then transformed into neutral, stable reactants. [Pg.571]

The use of computers for the design of chemical syntheses was first demonstrated by Corey and Wipke in 1969 with their program OCCS [30]. The successor to OCCS, LHASA [31], is generally considered to be the first synthon-based system. Its development is still going on. Currently, three groups are working on LHASA, one at Harvard University, USA [32], one at the University of Leeds, UK [33], and... [Pg.573]

Reagent A compound which reacts to give an intermediate in the planned synthesis or to give the target molecule itself. The synthetic equivalent of a synthon. [Pg.4]

Synthetic Equivalent A reagent carrying out the function of a synthon which caimot itself be used, often because it is too unstable. [Pg.4]

Synthon A generalised fragment, usually an ion, produced by a disconnection. (Some people also use synthon for a synthetic equivalent). [Pg.4]

You can see how the alkyl-lithium acts as tlie synthon CH3CH2 since the carbon-lithium bond breaks so that the electrons go with the carbon atom. Suggest a disconnection for TM 16. [Pg.7]

The synthetic equivalents of the synthon H" are the hydride donors sodium borohydride NaBH4, and lithium aluminium hydride LiAIHi. How might you make TM 21 using this disconnection ... [Pg.9]

The reagent for synthon A is an epoxide so that the reaction becomes ... [Pg.11]

The acetoacetate enolate ion (A in frame 54) is a reagent for the synthon B, the acetone anion. We shall discover how to add the COiEt activating group later. [Pg.19]

Protection and activation give us a reagent for the synthon CH2CO2H. AVe protect the acid as an ester and add another ester group as activation, giving malonic ester CH2(C02Et)2. How would you make TM 57 ... [Pg.19]

Analysis It may be tempting to disconnect bond a but this would giye the unknown and presumably yery unstable PhC=0 synthon. The better disconnection is bond b giying two carbonjd compounds. [Pg.28]

The reagent for the synthon RCO will be RCOX where X is a leaving group, such as OEt. So how would you make TM 94 ... [Pg.30]

So far aU our two group disconnections have sensible synthons with anions or cations all stabihsed by functional groups in the right positions. This won t always be the case. Supposing we wanted to make the hydroxy-acid TM 131 we could treat it as an alcohol ... [Pg.42]

Again we need a reagent for an acyl anion synthon (A). We find this in the acetyhde ion since substituted acetylenes can be hydrated to ketones ... [Pg.46]

The obvious diseonnection on a 1,4-dicarbonyl compoimd gives us a logieal nucleophilie synthon (an enolate anion) A but an illogieal electrophilic synthon B ... [Pg.54]

Synthesis Again the enamine can be used to proyide the enolate synthon ... [Pg.56]

Clearly other combinations of logical and illogical synthons could be used to make 1,4-dioxygenated compounds. How could you use cyanide ion (as the CO2H synthon) to make a y-keto acid such as... [Pg.58]

Acetylenes can be hydrated to give ketones (frame 145) so propargyl bromide must provide a MeCOCH2 synthon ... [Pg.58]

You will meet other combinations of logical and illogical synthons in review problems later. [Pg.58]

Synthesis The vinyl anion synthon can either be the vinyl Grignard reagent or the acetylide arrion, in which case the synthesis becomes ... [Pg.70]

The anion A is a reagent for the synthon H2N-CH-CO2H and amino acids are derived this way. How could you make TM 265 ... [Pg.85]

The synthon will be, in a lower valeney state - if X is C then it will be a carbene or the synthetic equivalent of a carbene. Let s see how this disconnection works out for epoxides. Taking X = O first we have... [Pg.90]

A reagent for the synthon is 6 aperacid RCOjH. How then could you make TM 276 ... [Pg.90]

The reagent for the synthon O changes when the olefin is electrophihc as in an a,p-unsaturated carbon3d compound then alkaline h3 drogen peroxide (HOO ) is usea. How could you make TM 278 ... [Pg.90]

The same disconnection can be used with simple epoxides when the sulphur ylid (A) is used a reagent for the synthon CH2. Draw a mechanism for the reaetion ... [Pg.92]

The same disconnection is also effective for cyclopropanes but the reagent for the earbene synthon is a diazocompound RCHN2 or a dihalo compound treated with a metal e.g. [Pg.93]

The vinyl anion synthon is best represented by an acetylide ion (frame 33). Synthesis ... [Pg.106]

Analysis Marking the common atoms we find there are three possible disconnections of bonds between them, but only a or c give us simpler precursors. Both also are logical in that we can immediately write reagents for the synthons. [Pg.109]

What possible synthons might we need for discormection c ... [Pg.110]

Both are possible but we are more used to (1) since we can use a Michael acceptor and cyanide ion for the two synthons. How would you actually do a s mthesis this way ... [Pg.110]

Analysis The carbene synthon is easy it can be ethyl diazoacetate NiCHCOiEt. The diene can be made by the Wittig reaction from a familiar aUylic bromide (TM 31). [Pg.115]

Now consider strategy b. How would you make the diene acid B, what reagent would you use for the carbene synthon, and how do you rate the chances of this route ... [Pg.116]

The carbene synthon might be difficult, but since the olefin is conjugated with a carbonyl group we could try a sulphur ylid as a nucleopliilic carbene equivalent (as in frame 283). Synthesis The diene could be made by this route ... [Pg.116]

Now we must introduce some functional groups to turn this synthon into a reagent. What do you suggest ... [Pg.119]

The formal carbanions and carbocations used as units in synthesis are called donor synthons and acceptor synthons. They are derived from reagents with functional groups. [Pg.1]

CH methyl acceptor synthon (from the reagent CHjI)... [Pg.1]


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1.3.2- Dioxathiolane oxides epoxide equivalents and versatile synthons

2-Oxyallyl synthons

2-Oxyallyl synthons 3 + 2] cycloaddition reactions

2.6- Naphthyridines from pyridines with synthon

3-Hydroxy acids as chiral synthons

Acceptor synthon

Acceptor synthons

Acceptor synthons alkyl

Acceptor synthons oxygen

Acceptor synthons umpolung

Acetate enolate synthon, chiral

Acetoacetic ester synthons

Acyl anion synthon

Acyl anion synthon 1,3-dithiane anions

Acyl radical, synthon

Addition Reactions of Activated Synthons

Aldol cyclization chiral synthons for

Alkaloid synthons, synthesis

Alkanes, nitroacyl anion synthons

Alkanes, nitroacyl anion synthons Henry reaction

Alkanes, nitroacyl anion synthons functionalized

Alkanes, nitroacyl anion synthons preparation

Alkenes synthon generation

Alkyl anion synthons

Alkyl anion synthons reagents

Alkyl synthons

Alkylating and d-Synthons

Allyl anion synthon

Allyl d-synthons

Allyl synthons

Amides synthon generation

Amines synthons

Amino acids as synthons for heterocyclic

Amino acids as synthons for heterocyclic compounds

Amino acids synthons

Amino adds synthons

Annulating synthons

Annulating synthons for highly

Approaches carbohydrate synthons

Aromatic synthon

Aromatic synthon synthesis

Basic Principles Synthons and Reagents Synthesis of Aromatic Compounds

Biocatalytic Approaches for the Large-Scale Production of Asymmetric Synthons

Bivalent synthons

C-3 synthons

C3-synthon

Calixarenes - essential supramolecular synthons

Carbohydrate synthons

Carbon monoxide: carbonyl synthon

Carboxylic acid dimer synthon

Carboxylic acids synthons

Cation-anion synthons

Chiral Nickelacycles as Amino Acid Synthons

Chiral Synthon

Chiral synthon for 2-aminoalcohols

Chiral synthon with yeast

Chiral synthons

Chiral synthons lipases

Chiral synthons synthetic applications

Chiral three-carbon synthons

Cj-synthon

Combined Effect of Synthons and Shape

Compactin lactone synthon

Convergent lactone synthon

Crystal engineering supramolecular synthons

Crystal engineering synthons

Crystal synthon approach

Cyclization reactions synthons

Cycloaddition reactions synthons

D* synthon

D-Synthons

D1 synthon

D2 synthon

Deconstructing the Supra-Molecular Interactions at Surfaces - Extrinsic Synthons

Deconstructing the Supra-Molecular Interactions in Bulk - Intrinsic Synthons

Dichlorocarbene Addition to Allylic Alcohols A Cyclopentenone Synthon

Disconnection, Synthons, Introductory Example

Disconnections, Synthons, and Synthetic Equivalents

Donor angle of incidence to a-synthons

Donor synthon

Donor synthons

Donor synthons by nitrogen

Donor synthons by phosphorus

Donor synthons by silicon

Donor synthons by sulfur

Donor synthons definition

Donor synthons reactions

Donor synthons stabilization

Donor synthons substituted cyclopropanes

Drug synthesis synthons

E-Synthon

E-Synthons

Electron Acceptors (Electrophiles, a-Synthons)

Enamines as synthons in the synthesis

Enamines as synthons in the synthesis heterocycles

Enantioselective Synthesis of Propargyl Alcohols as Multifunctional Synthons

Enolates synthons representing

Ester enolates synthons

Formyl anion synthon, reagent equivalents

Formyl anions, synthons

Formylation: a(-synthons

From Four or More Synthons

From Three Synthons

From a Benzene Derivative as Substrate and One Synthon

From a Benzene Substrate with Two or More Synthons

From a Benzene Substrate with an Ancillary Synthon

From a Pyrazine Substrate with or without Synthon(s)

From a Pyridine Substrate and Synthon(s)

From a Pyridine Substrate and Two Synthons

From a Pyridine Substrate with One Synthon

From a Pyridine Substrate with Two or More Synthons

From a Single Six-Atom Synthon

Glycine synthons

Glycosyl synthon, synthesis

Graph synthon

Graph synthon-reaction

Homoenolate synthons

Hydrogen Bond Synthons - Common and Exotic

Hydrogen bond synthons

Hydrogen bonded supramolecular synthons

Intermolecular synthon

Intermolecular synthons

Isostructural synthons

Isostructurality Based on Interchangeability of Supramolecular Synthons

Ketones synthon representing

Key-lock, template and hand-glove synthon interactions

Lactone synthon

Matrix synthon-reaction

Methyl acrylate synthon

Methylene synthons

Model of synthon

Model of synthon reactions

Molecular computers based on synthon interactions

Molecular recognition - synthons

Naphthyridines by Cyclocondensation of Pyridine Substrates with Synthons

Natural and unnatural products from sugar synthons

Natural synthons

Nitrile ylides synthon generation

Nitrile ylides, synthon formation

Oligosaccharide synthons, synthesis

Optically pure synthons, biocatalytic

Optically pure synthons, biocatalytic pharmaceutical industry

Organic chemistry, synthons

P-lactam synthon method

PRIMARY SYNTHESES FROM ALIPHATIC OR CARBOCYCLIC SYNTHONS

Pharmaceutical industry, biocatalytic pure synthons

Pharmaceuticals synthons

Polarity, synthons

Propargyl synthons

Pyridine synthons

R -synthons

Radical synthons

Radical synthons alkyl

Reagents. Equivalents. Synthons

Regioselectivity synthon formation

Retrosynthetic analysis disconnections/synthons/synthetic

Retrosynthetic analysis synthons

Silane, methoxy methylformyl anion synthon

Silane, methoxybis methylmethoxycarbonyl anion synthon

Silyl carbonates synthons

Subject synthons

Sugar synthons

Supramolecular architectures based on the carboxylic acid dimer synthon

Supramolecular self assembly using synthons and secondary building units

Supramolecular synthon

Supramolecular synthons

Supramolecular synthons Subject

Supramolecular synthons crystal packing

Supramolecular synthons hierarchy

Supramolecular synthons homosynthons

Supramolecular synthons solid-state structure

Supramolecular synthons yield

Synthesis of unlabelled synthons

Synthon Analysis

Synthon ammonia

Synthon approach

Synthon carboxyl dimer

Synthon concept

Synthon isomeric

Synthon method

Synthon robust

Synthon stable

Synthon unstable

Synthon, definition

Synthon-Influential Bond Scission

Synthons

Synthons

Synthons Claisen rearrangements

Synthons acyl anion

Synthons acyl cation

Synthons allylic

Synthons allylic alkylation

Synthons amide anion

Synthons amino acid enolates

Synthons and supramolecular chemistry

Synthons are idealized reagents

Synthons asymmetric syntheses

Synthons bipolar

Synthons carbanion

Synthons carbonyl cation

Synthons conjugate additions

Synthons ester

Synthons extrinsic

Synthons illogical

Synthons intrinsic

Synthons vinyl anion

Synthons, haloalkenes

Synthons, synthesis

Synthons, three-carbon

Synthons: definition

Tectons and Synthons

The Synthon Approach

The Synthon Approach as a Pragmatic Tool in Elaborating Viable Synthetic Pathways

Three-carbon synthons, annulations

TiSler, M., Kolar, P„ Amino Acids as Synthons

TiSler, M., Kolar, P„ Amino Acids as Synthons for Heterocyclic Compounds

To optically pure synthons for

Two Important Synthons for Ester Enolates

Umpoled synthon

Umpolung Synthons

Unnatural products synthons

Unnatural synthons

Unnatural synthons electrophilic

Unnatural synthons nucleophilic

Unsaturated carbohydrate synthon

Using a Diacid (Oxalic Acid) as Synthon

Using a Diacyl Dihalide (Oxalyl Halide) or Related Synthon

Using a Dialdehyde (Glyoxal) or Related Synthon

Using a Diamide (Oxamide), Amido Nitrile, or Related Synthon

Using a Diketone or Related Synthon

Using a Keto Acid or Related Synthon

Using a Keto Amide, Nitrile, Acyl Halide, or Related Synthon

Using a Keto Ester or Related Synthon

Using an Aldehydo Acid or Related Synthon

Using an Aldehydo Amide, Nitrile, Acyl Halide, or Related Synthon

Using an Aldehydo Ester or Related Synthon

Using an Aldehydo Ketone or Related Synthon

Using an Estero Amide, Nitrile, Acyl Halide, or Related Synthon

Versatile synthon

Versatile synthons in heterocyclic synthesis

Vinyl anion synthon

Vinyl cation synthons

Vitamin D synthons

Where Synthons Provide Nl

Where the Synthon Supplies One Ring Atom

Where the Synthon Supplies Three Atoms

Where the Synthon Supplies Three or More Ring Atoms

Where the Synthon Supplies Two Atoms

Where the Synthon Supplies Two Ring Atoms

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