Barry Snider

Snider, B. B.; Buckman, B. O. “Manganese(III) Based Oxidative Free-Radical Annulations” Tetrahedron 1989, 45, 6969-6978. http://dx.doi.org/10.1016/S0040-4020(01)89163-8 

Reaction of diethyl allylmalonate (6b), sterically accessible nucleophilic alkenes, Mn(OAc)3·2H2O and Cu(OAc)2·H2O gives methylenecyclopentanes 10. 

Snider, B. B.; Ke, Y. “Synthesis of (-)-Reiswigin A. Assignment of Absolute and Relative Configuration” Tetrahedron Lett. 1989, 30, 2465-2468. http://dx.doi.org/10.1016/S0040-4039(01)80426-3 

The synthesis of the anti-viral agent (-)-reiswigin A (1) was accomplished in 8 steps in 7% overall yield. The absolute stereochemistry and configuration of the side chain methyl group of the natural product were assigned as shown in 17. 

Snider, B. B. “Alkylaluminum Halide Induced Reactions of Carbonyl Compounds with Unactivated Alkenes” NATO ASI Ser., Ser. C 1989, 289 (Selectivities in. Lewis Acid Promoted Reactions), 147-67. 

Ruben, R. L.; Snider, B. B.; Hobbs, F. W., Jr.; Confalone, P. N.; Dusak, B. A. “Cytotoxicity of Synthetic Racemic Ptilocaulin: A Novel Cyclic Guanidine” Invest. New Drugs 1989, 7, 147-154. http://dx.doi.org/10.1007/BF00170851 

Ptilocaulin showed a fairly broad spectrum of in vitro activity against colon and mammary adenocarcinomas, melanomas, leukemias, transformed fibroblasts and normal lymphoid cells (IC50s 0.05- > 10 μg/ml). 

Snider, B. B.; Walner, M. “Preparation of Unsaturated α,α-Dichloro Acid Chlorides and Intramolecular [2 + 2] Cycloadditions of the α-Chloro Ketenes Reductively Generated from them. Effect of Double Bond Geometry on the Cycloaddition” Tetrahedron 1989, 45, 3171-3182. http://dx.doi.org/10.1016/S0040-4020(01)80143-5 

Snider, B. B .; Patricia, J. J. “Manganese(III)-Based Oxidative Free-Radical Cyclizations. Oxidative Cyclization and Aromatization of 3-Oxo-6-heptenoate Esters” J. Org. Chem. 1989, 54, 38-46. http://dx.doi.org/10.1021/jo00262a016 

Snider, B. B.; Beal, R. B. “Total Synthesis of Sesquiterpenes via Intramolecular Ketene Cycloadditions. Isocomene, α-cis– and α-trans-bergamotenes. An Approach to Seychellene” J. Org. Chem. 1988, 53, 4508-4515. http://dx.doi.org/10.1021/jo00254a017 

Snider, B. B.; Niwa, M. “Intramolecular Cycloadditions of Arylketenes with Alkenes. Reaction of 5-Arylbicyclo[3.2.0]heptan-6-ones” Tetrahedron Lett. 1988, 29, 3175-3178. http://dx.doi.org/10.1016/0040-4039(88)85114-1 

Intramolecular cycloadditions of arylketenes 4 proceed in excellent yield to give 5-arylbicy-clo[3.2.0]heptan-6-ones 5. 

Merritt, J. E.; Sasson, M.; Kates, S. A.; Snider, B. B. “Formation of Seven- and Eight-Membered Rings by Manganese(III)-Based Oxidative Free Radical Cyclization” Tetrahedron Lett. 1988, 29, 5209-5412. http://dx.doi.org/10.1016/S0040-4039(00)80718-2 

Oxidative free radical cyclizations of β-ketoesters 1 with Mn(OAc)3·2H2O and Cu(OAc)2·H2O proceeds in moderate yield to give seven- and eight-membered rings. The regiochemistry of the cyclization and oxidative termination are described. 

Snider, B. B. “Intramolecular Cycloaddition Reactions of Ketenes and Keteniminium Salts with Alkenes” Chem. Rev. 1988, 88, 793-811. http://dx.doi.org/10.1021/cr00087a005 

Snider, B. B.; Allentoff, A. J.; Kulkarni, Y. S. “Type III Intramolecular [2 + 2] Cycloadditions of Vinylketenes” J. Org. Chem. 1988, 53, 5320-5328. http://dx.doi.org/10.1021/jo00257a022 

Lee, S. Y.; Kulkarni, Y. S.; Burbaum, B. W.; Johnston, M. I.; Snider, B. B. “Type I Intramolecular Cycloadditions of Vinylketenes” J. Org. Chem. 1988, 53, 1848-1855. http://dx.doi.org/10.1021/jo00244a002 

Lee, S. Y.; Niwa, M.; Snider, B. B. “Type II intramolecular [2 + 2] Cycloadditions of Alkenes with Alkylvinylketenes. Synthesis of Methyl Jasmonate” J. Org. Chem. 1988, 53, 2356-2360. http://dx.doi.org/10.1021/jo00245a044 

Snider, B. B.; Patricia, J. J.; Kates, S. A. “Mechanism of Manganese(III)-Based Oxidation of β-Keto Esters” J. Org. Chem. 1988, 53, 2137-2143. http://dx.doi.org/10.1021/jo00245a001 

The rate-determining step in the oxidation of 2-substituted acetoacetate esters by Mn(OAc)3 is the loss of a proton from the Mn(III) complex to give a radical. The rate-determining step in the oxidation of 2-unsubstituted acetoacetate esters by Mn(OAc)3 in the presence of an alkene is the addition of the alkene to the Mn(III) complex to give the addition product. In the absence of alkene, a much slower electron transfer from the enolate to the oxo-centered metal system is the rate-determining step. 

Snider, B. B.; Johnston, M. I. “Synthesis of Deoxytabtoxinine-b-lactam” Synth. Commun. 1987, 17, 1877-1886. http://dx.doi.org/10.1080/00397918708057798 

Deoxytabtoxinine-β-lactam (12) was synthesized in 6 steps from 3. β-Lactam 12 does not inhibit glutamine synthetase indicating that the hydroxyl group of tabtoxinine-β-lactam (2) is necessary for inhibition of glutamine synthetase. 

Snider, B. B.; Dombroski, M. A. “Manganese(III)-Based Oxidative Free Radical Cyclizations. 5. Termination of Polycyclization by Oxidative b-Hydride Elimination” J. Org. Chem. 1987, 52, 5487-5489. http://dx.doi.org/10.1021/jo00233a042 

Johnston, M. I.; Kwass, J. A.; Beal, R. B.; Snider, B. B. “Stereochemical Studies of Type-II Intramolecular Ene Reactions of d,e-Unsaturated Aldehydes” J. Org. Chem. 1987, 52, 5419-5424. http://dx.doi.org/10.1021/jo00233a021 

Snider, B. B.; Ron, E.; Burbaum, B. W. “Type II Intramolecular [2 + 2]-Cycloaddition of Alkenes with Vinylketenes Prepared by the Regiospecific Deprotonation of β,β-Disubstituted α,β-Unsaturated Acid Chlorides” J. Org. Chem. 1987, 52, 5413-5419. http://dx.doi.org/10.1021/jo00233a020 

Kulkarni, Y. S.; Niwa, M.; Ron, E.; Snider, B. B. “Synthesis of Terpenes Containing the Bicyclo[3.1.1]heptane Ring System by the Intramolecular [2 + 2] Cycloaddition Reaction of Vinylketenes with Alkenes. Preparation of Chrysanthenone, β-Pinene, β-cis-Bergamotene, β-trans-Bergamotene, β-Copaene, and β-Ylangene and Lemnalol” J. Org. Chem. 1987, 52, 1568-1576. http://dx.doi.org/10.1021/jo00384a035 

Snider, B. B.; Kulkarni, Y. S. “Preparation of Unsaturated α-Chloro Acids and Intramolecular [2 + 2] Cycloadditions of the Chloroketenes Derived from Them” J. Org. Chem. 1987, 52, 307-310. http://dx.doi.org/10.1021/jo00378a036 

Mohan, R.; Kates, S. A.; Dombroski, M. A.; Snider, B. B. “Manganese(III) Based Oxidative Free Radical Cyclization. 3. Polycyclization Reactions Proceeding Through Secondary Radicals” Tetrahedron Lett. 1987, 28, 845-848. http://dx.doi.org/10.1016/S0040-4039(01)81004-2 

Oxidative cyclizations of 3 with Mn(OAc)3 ·2H2O gives the tricyclic product 6 in good yield. This reaction proceeds through monocyclic secondary radical 4, which adds to the benzene ring to give 5 prior to the second oxidation. 

Snider, B. B.; Mohan, R.; Kates, S. A. “Manganese(III) Based Oxidative Free Radical Cyclizations. 2. Polycyclization Reactions Proceeding Through Tertiary Cations” Tetrahedron Lett. 1987, 28, 841-844. http://dx.doi.org/10.1016/S0040-4039(01)81003-0