132439-89-5

Upstream product

• 120783-47-3 α-(allyloxy)phenylacetaldoxime 
• 5153-67-3 nitrostyrene 
• 107-18-6 allyl alcohol 
• 102-96-5 (2-nitroethenyl)benzene 
• 7028-48-0 Phenylacetaldehyde oxime 
• 132439-80-6 1-allyloxy-2-nitro-1-phenylethane 
• 103-71-9 phenyl isocyanate 
• 110910-99-1 2-bromophenylacetaldehyde O-(trimethylsilyl)oxime 
• 75314-25-9 phenylacetaldehyde O-(trimethylsilyl)oxime 

Downstream Products

• 120783-53-1 4-Hydroxymethyl-2-phenyl-dihydro-furan-3-one 

Relevant academic research and scientific papers

Oxidative tandem alkoxide conjugate addition to nitroalkenes/radical 5-exo cyclizations - A versatile synthesis of functionalized 3-nitrotetrahydrofurans

Structurally diverse functionalized 4-(1-haloalkyl)-3-nitrotetrahydrofurans were conveniently obtained in moderate to good yield and moderate to very good diastereoselectivity by an oxidative tandem process consisting of conjugate addition reaction of lit

Sequential 1,3-dipolar cycloadditions in the synthesis of bis-isoxazolo substituted piperidinones

A strategy for the efficient synthesis of novel bis-isoxazolo substituted piperidinones has been developed. The protocol consists of the Michael addition of an unsaturated alkoxide to β-nitrostyrene followed by an intramolecular nitrile oxide cycloaddition (INOC) or an intramolecular silyl nitronate olefin cycloaddition (ISOC) to give III. Grignard addition to this isoxazoline intermediate followed by DCC coupling of the resulting isoxazolidine with nitroacetic acid gave II, and a second intramolecular cycloaddition via 1,3-dipoles result in the formation of the targeted novel tetracycles (I). A solid-supported scavenger was employed to increase the efficiency and yield of the Michael addition step.

One-pot synthesis of five-membered cyclic thioethers or ethers via intramolecular nitrile oxide-olefin cycloaddition (INOC) or intramolecular alkoxycarbonyl nitronate-olefin cycloaddition (IAOC) by the use of methyl chloroformate

Reaction of β-nitrostyrenes 1 with allyl mercaptan 2 in the presence of triethylamine generated unsaturated nitro sulfides 3 and then the solution was treated with methyl chloroformate (MCF) and was refluxed to obtain [3.3.0]bicyclic products trans-6 and cis-6 in one-pot. The ratios of trans- 6:cis-6 were from 1.1:1 to 1.8:1 and the mechanism of the formation 6 is proposed to proceed through the formation of nitrile oxides 5 to undergo intramolecular nitrile oxide-olefin cycloaddition (INOC). Nitronates 16, prepared from 1 with allyl alcohol and base, can be converted into methoxycarbonyl nitronates 22 by treating the solution with methyl chloroformate and catalytic amount of 4-dimethylaminopyridine (DMAP) in the presence of different amounts of triethylamine. Intermediates 22 can either undergo intramolecular alkoxycarbonyl nitronate-olefin cycloaddition (IAOC) to generate highly stereoselective product trans-14 or undergo INOC to yield trans-14 and cis-14. The application of this improved methodology to synthesize different heterocyclic products 10, 26, and 27 is reported.

High stereoselectivity in one-pot intramolecular cycloadditions of olefinic silyl nitronates

Intramolecular silyl nitronate olefin cycloaddition starting from nitro olefins 1 and leading to substituted tetrahydrofuran rings fused to isoxazolines 5 has been achieved in a one-pot protocol involving Michael addition, silylation, cycloaddition, and desilylation steps. The results show that unlike nitrile oxides, silyl nitronates undergo highly stereoselective intramolecular cycloadditions to produce functionalized heterocyclic rings.

Cycloadditions, 55: Substituent effects in tandem intramolecular silyl nitronate olefin cycloadditions (ISOC) leading to functionalized tetrahydrofurans

The intramolecular silyl nitronate olefin cycloaddition (ISOC) leading to substitued, fused-ring tetrahydrofurans 6 was examined with regard to optimum conditions and substituent effects. The required unsaturated nitro ethers 3 resulted from low-temperature, base-mediated Michael addition of allyl alcohols 2 to nitroolefins 1, followed by conversion to unsaturated silyl nitronates 4. Cycloaddition of the latter and elimination of silanol provided 6. One-pot tandem reactions, starting with nitroolefins 1 and allyl alcohols 2 and involving four steps, sometimes proceeded in better yields but often gave unexpected side products. Terminal olefinic electron-donating substituents (Me, MeO) increased the rate of cycloaddition, while an internal olefinic methyl substituent slowed down the reaction. In the case of nitronates possessing ester or nitrile moieties as terminal olefin substituents, tandem Michael addition to produce substituted furans 14, 15 occurred faster than trapping of the nitronate anion by TMSCl. VCH Verlagsgesellschaft mbH, 1997.

Stereoselective formation of functionalized 2-aryl-tetrahydrofurans from aromatic aldehydes via intramolecular 1,3-dipolar cycloadditions (INOC and IOOC)

α-Allyloxyaldoximes 8, formed by the reduction of β-nitrostyrenes 5 with SnCl2-2H2O in the presence of an unsaturated alcohol, undergo either thermally induced intramolecular oxime olefin cycloaddition (IOOC) to bicyclic isoxazolidines 7, with stereospecific introduction of three stereocenters, or nitrile oxide olefin cycloadditions (INOC) to bicyclic isoxazolines 6. This provides an entry into functionalized tetrahydrofurans and tetrahydropyrans.

Double diastereoselectivity in the intramolecular nitrile oxide-olefin cycloaddition (INOC) reaction

An investigation of relative asymmetric induction and double diastereoselectivity in the intramolecular nitrile oxide-olefin cycloaddition (INOC) reaction is presented.

A Route to Functionalized Cyclic Ethers by Intramolecular Cycloaddition of Unsaturated Nitro Ethers

A convenient conversion of aldehydes via nitroolefins 2 into cyclic ethers 6 fused to an isoxazoline ring involves formation of unsaturated nitroalkyl ethers 4 and subsequent intramolecular cycloaddition of an in situ-formed nitrile oxide olefin.The cyclization proceeds with stereoselective formation of trans over cis isomers in the tetrahydrofuran series and opposite stereoselectivity in the tetrahydropyran and hexahydrooxepine series, depending on the substituent R in the original nitro compound, thus providing access to stereoselectively functionalized cyclic ethers.

Conversion of Unsaturated Alcohols into Functionalized Tetrahydrofurans and Tetrahydropyrans via Nitrile Oxide Dipolar Cycloadditions

The intramolecular nitrile oxide cycloaddition (INOC) of a series of unsaturated oximino ethers has been investigated.The synthesis of the olefinic nitrile oxides involves treating an unsaturated alcohol with a α-bromoalkanal O-(trimethylsilyl)oxime in the presence of fluoride ion followed by subsequent sodium hypochlorite oxidation.The nitrile oxides were not isolated but spontaneously underwent intramolecular cycloaddition to give fused five- and six-membered ring ethers.The preferred stereoisomer in the formation of the five-membered ring ethers is trans, whereasin the six-membered ring ethers the cis isomer predominates.MM2 calculations help rationalize the observed stereoselectivity.The ratio of diastereomeric products from the INOC reaction appears to correlate with product stabilities.Simple heating of some of the oximino ethers led to intramolecular cycloaddition.The ring closure apparently proceeds subsequent to a tautomeric equilibration of the oxime with a transient nitrone which is trapped by the neighboring ?-bond.

FORMATION OF FUNCTIONALIZED CYCLIC ETHERS BY INTRAMOLECULAR NITRILE OXIDE CYCLOADDITIONS

The reaction of O-trimethylsilyl α-bromo aldoximes with unsaturated alcohols produces oximino ethers which can be readily oxidized with sodium hypochlorite.The transient nitrile oxide intermediate formed undergoes spontaneous cyclization affording fused i