71309-70-1

Upstream product

• 542-28-9 3,4,5,6-tetrahydro-2H-pyran-2-one 
• 75-77-4 chloro-trimethyl-silane 

Downstream Products

• 71309-71-2 2-phenylthiomethyl-δ-valerolactone 
• 72653-58-8 2-(1-phenylthiobutyl)-δ-valerolactone 
• 115095-48-2 2-(((p-nitrophenyl)sulfonyl)oxy)valerolactone 
• 139367-47-8 (R*,S*)-2--5-pentanolide 
• 139367-47-8 (R*,R*)-2--5-pentanolide 
• 139620-54-5 3-Phenyl-8a-trimethylsilyloxy-4,4a,5,6-tetrahydro-7H,8aH-pyrano<3,2-e>-1,2-oxazine 
• 139620-61-4 3-(p-Chlorophenyl)-8a-trimethylsilyloxy-4,4a,5,6-tetrahydro-7H,8aH-pyrane<3,2-e>-1,2-oxazine 
• 87532-11-4 α-(benzoyloxy)-δ-valerolactone 
• 139367-50-3 (R*,S*)-2--5-pentanolide 
• 139367-50-3 (R*,R*)-2--5-pentanolide 
• 95723-21-0 1,4-dibenzyl-3-(2'-thiopyridyl)-6-(2-valerolactonyl)-2,5-piperazinedione (syn, minor diastereomer) 
• 95676-20-3 1,4-dibenzyl-3-(2'-thiopyridyl)-6-(2-valerolactonyl)-2,5-piperazinedione (syn, major diastereomer) 
• 95676-23-6 1,4-bis(p-methoxybenzyl)-3-(2'-thiopyridyl)-6-(2-valerolactonyl)-2,5-piperazinedione (syn, minor diastereomer) 
• 95723-22-1 1,4-bis(p-methoxybenzyl)-3-(2'-thiopyridyl)-6-(2-δ-valerolactonyl)-2,5-piperazinedione (syn, major diastereomer) 

Relevant academic research and scientific papers

A simple thiophosphate-based method for α-alkylidenation of lactones

A variety of α-alkylidene lactones has been synthesized using a one-pot procedure based on the reaction of readily available thiophosphates with aldehydes under basic, mild conditions. Georg Thieme Verlag Stuttgart.

Lewis Acid Catalyzed Synthesis of α-Trifluoromethyl Esters and Lactones by Electrophilic Trifluoromethylation

An electrophilic trifluoromethylation of ketene silyl acetals (KSAs) by hypervalent iodine reagents 1 and 2 has been developed. The reaction proceeds under very mild conditions in the presence of a catalytic amount of trimethylsilyl bis(trifluoromethanesulfonyl)imide (up to 2.5 mol %) as a Lewis acid providing a direct access to a variety of secondary, tertiary, and quaternary α-trifluoromethyl esters and lactones in high yield (up to 98%).

The mukaiyama aldol reactions for congested ketones catalyzed by solid acid of tin(IV) ion-exchanged montmorillonite

Tin(IV) ion-exchanged montmorillonite (Sn-Mont) was found to be an excellent solid acid catalyst for the Mukaiyama aldol reactions of congested ketones with silicon enolates from ketones as well as esters. It was disclosed that Sn-Mont was far more active than other metal ion-or proton-exchanged montmorillonites and typical homogeneous acid catalysts such as TMSOTf and BF3?OEt2.

Synthetic studies towards the core structure of nakadomarin a by a thioamide-based strategy

The tricyclic BCD substructure of the marine natural product nakadomarin A has been synthesised. The strategy utilised a key carbon-carbon bond-forming reaction between a furan and an N-acyliminium ion derived from a secondary thiolactam. In addition, a novel three-component coupling reaction between a thioamide, an allylic bromide and an isocyanate, leading to the establishment of two new stereogenic centres, is reported. Two key steps in a projected total synthesis of nakadomarin A have been realised by using the unique chemistry of thioamides. Formation of the carbocyclic B ring can be effected by nucleophilic attack of a furan on a thiolactam-derived iminium ion, and the key quaternary centre can be established by a novel three-component coupling reaction.

Natural product biosynthesis inspired concise and stereoselective synthesis of benzopyrones and related scaffolds

A natural product biosynthesis-inspired strategy to explore biologically relevant chemical space is presented. A phosphine-catalyzed cascade and stereoselective annulation provides a common tricyclic benzopyrone intermediate that was efficiently transformed into diverse and related naturally occurring scaffolds

A stereoselective cyclisation cascade mediated by SmI2-H 2O: Synthetic studies towards stolonidiol

A cascade reaction involving sequential conjugate reduction, stereoselective aldol cyclisation and chemoselective lactone reduction mediated by SmI2-H2O provides access to a cyclopentanol bearing two vicinal quaternary stereocentres with good stereocontrol. The functionalised cyclopentanol product has been converted to a key intermediate in ongoing asymmetric studies towards stolonidiol.

Studies on the α-acetylation of δ-valerolactone and ε-caprolactone

The synthetic approach to α-acetylated δ-valero- (7a) and ε-caprolactone (7b) is reported. While 7a was isolated in 21% yield from the respective iodoester 5a by an alkylation sequence involving transesterification and Finkelstein reaction, 7b was not obtained from 5b but the dimer 8. Also transesterification and olefin ring closing metathesis (RCM) failed to prepare 7b. RCM resulted in the dimeric lactone 10, showing that the formation of 14-membered rings is favored over that of seven-membered rings. A Mukaiyama-type Claisen reaction finally gave α-acetyl lactones 7a and 7b in practically useful quantity of about 10 g (62% yield): starting lactones 13a,b were converted to silylenolethers 14a,b, which were acetylated with acetic anhydride in presence of the Lewis acid catalyst TiCl4. However, acetylation depends on the addition sequence of starting materials: if the mixture of Ac2O/TiCl4 is added to 14b, lactone 7b can be further converted to give bis-oxepanonyl ethanols 15a,b. Both compounds 15 were characterized by X-ray crystallography and NMR.

α-ALKYLATION AND α-ALKYLIDENATION OF CARBONYL COMPOUNDS BY O-SILYLATED ENOLATE PHENYLTHIOALKYLATION

For many reactions next to a carbonyl group, the use of O-silylated enolate chemistry offers improvements in yield and selectivity over the corresponding reactions of Group I metal enolates.In the case of α-alkylation of carbonyl compounds, Lewis acid (TiCl4 or ZnBr2) promoted phenylthioalkylation of O-silylated enolates 3 by α-chlorosulphides 4 (R3=H, Me, Prn, Pri, Bui, and Me3Si), followed by reductive sulphur removal by Raney nickel, 5->6, is found to be a reliable method for this synthetically important C-C bond forming step.An alternative sulphur elimination pathway via the sulphoxide, 5->7, allows the regio- and stereocontrolled α-alkylidenation of carbonyl compounds.The phenylthioalkylation reaction is applicable to ketones, aldehydes, esters, and lactones.

ETUDE DE LA REACTION CHLOROCARBENE-ACETALS DE CETENES. I. SYNTHESE D'ESTERS α,β-ETHYLENIQUES.

The reaction of chloro, chloromethyl and chlorophenyl carbenoids with ketene alkylsilylacetals has been studied.Excellent yields of cyclopropanation were observed and the unstable chlorocyclopropanone acetals formed were thermally rearranged in high yield into α-substituted α,β-ethylenic esters.This new method for the synthesis of unsaturated esters appeared complementary of the known-ones.

PALLADIUM-CATALYZED PREPARATION OF α-ALLYL ESTERS AND α,β-UNSATURATED ESTERS FROM SATURATED ESTERS VIA THEIR KETENE SILYL ACETALS

Reaction of ketene silyl acetals with allylic carbonates in the presence of palladium-phosphine catalyst in dioxane gives α-allyl esters in high yields.When the reaction is carried out with phosphine-free palladium catalyst in nitriles, α,β-unsaturated esters are obtained in good yields.