Addition of methanol to hexynedioic esters. Synthesis of cyclopentanediones and muconates

Landesberg, J. M.; Kellner, Dominik

doi:10.1021/jo01273a003

Cited by 5 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…

…”

mentioning

confidence: 88%

Pyrolysis studies of organic oxygenates. 5. Thermal chemistry pathways of 1-naphthol under hydrogen

Schlosberg¹,

Kurs²

1984

J. Org. Chem.

View full text Add to dashboard Cite

higher ratios over the entire range investigated supports this assumption. (2) Although the nature of the interacting lanthanide reagent species cannot be unequivocally established nor critically inferred from these results, it seems likely that a large contribution from partially dissociated species, i.e., Yb(fod)2+ or Yb(fod)2+ is present. The low polarity solvent does not favor dissociation of the shift reagent but the strong binding ability of the lariat ethers could surely enhance the stability of the dissociated species, perhaps even that of Yb3+. This kind of ligand displacement reaction as opposed to the more common ligand number expansion, although unprecedented, would explain the relatively large LIS values of the side-arm carbon atoms. If the interacting species were Yb(fod)3, it would be sterically difficult for the side-arm donor groups to interact with the lanthanide metal center. Further studies are currently underway to establish the nature of the interacting lanthanide reagent species with the lariat ethers. ConclusionsThe use of lanthanide shift reagents provides some insight into the structures of lanthanide ion complexes with lariat ethers. Ytterbium complexation by ligands 1 and 2 was studied by this novel approach. LIS data clearly indicate that the substitution position of the methoxy group in the benzene ring is the key to side-arm participation in the interaction with the ytterbium cation. In this way, our results demonstrate binding cooperativity in the case of the o-methoxy lariat (structure 1) while no such side-arm-ring cooperativity is evident for the p-methoxy lariat (structure 2). However, in both ligands, the crown macroring is, as expected, the main complexation site.

show abstract

“…

…”

mentioning

confidence: 88%

Pyrolysis studies of organic oxygenates. 5. Thermal chemistry pathways of 1-naphthol under hydrogen

Schlosberg¹,

Kurs²

1984

J. Org. Chem.

View full text Add to dashboard Cite

show abstract

“…A sample of 6 (0.1 g) was decomposed at the melting point; the infrared spectrum of the oil which resulted was identical in all respects with the infrared spectrum of 4,4-dimethyl-3-methoxy-2cyclopenten-l-one (2). 1 Attempts to isolate 3 from chloroform solutions using standard poedures for unstable compounds only resulted in the recovery of 2 and 6.…”

Section: Experimental Section9mentioning

confidence: 99%

“…The principal peaks in the mass spectrum of 6 are as follows: MS (75 eV) m/e (rel intensity) 184 (1), 151 (2), 141 (8), 140 (57), 139 (25), 126 (9), 125 (100), 111 (5). This contrasts to the principal peaks in the mass spectrum of 5:1 MS (75 eV) m/e (rel intensity) 184 (95), 169 (84), 154 (31), 153 (100), 152 (31), 137 (44), 126 (48).…”

Section: Experimental Section9mentioning

confidence: 99%

Formation of a stable Enol from a Michael addition

Landesberg¹

1975

J. Org. Chem.

Self Cite

View full text Add to dashboard Cite

Notes trichloride (2.3 g, 15.0 mmol) was weighed under dry nitrogen in a glove bag and placed under nitrogen in a 100-ml three-neck flask with 70 ml of dry glyme. L1AIH4 (190 mg, 5.0 mmol) was quickly added to the stirred T1CI3 slurry, and the resulting black suspension was stirred for 10 min before use. B. Alternatively, a 3:1 TiCls-L1AIH4 premix (effective mol wt 167, 2.50 g, 15.0 mmol) was weighed under nitrogen in a glove bag and added to 70 ml of dry glyme under nitrogen. The resulting black suspension was stirred for 10 min before use.The substrate alcohol (5.0 mmol) in several milliliters of glyme was then added, and the reaction mixture was refluxed for 16 hr. After cooling, the reaction mixture was quenched by addition of dilute aqueous hydrochloric acid, then diluted with water and extracted with ether. The ether extracts were combined, washed with brine, dried (MgSCX), filtered, and concentrated at the rotary evaporator. Crude products were then purified either by crystallization or distillation. In this manner, the following reactions were run.Benzyl alcohol gave bibenzyl, 78%, mp 51-51.5°(lit.8 mp 52°).-Phenethyl alcohol gave a liquid mixture of meso and dl forms of 2,3-diphenylbutane, 68%.

show abstract

Conjugate Addition Reactions of Organocopper Reagents

Posner

2011

Organic Reactions

View full text Add to dashboard Cite

Addition of an organometallic reagent to alpha,beta‐usaturated carbonyl compounds occurs in one or both of two modes: attack at the carbonyl function produces a 1,2 adduct, whereas reaction with the entire system gives a 1,4 adduct. Organoalkali metal reagents derived from unstabilized carbanions generally add across the carbonyl group, where as enolate and other stabilized anions usually undergo a Michael addition, introducing a carboalkyl group at the beta carbon. Grignard reagents normally give 1,2 adducts. The wide scope of these reagents has made conjugate addition of alkyl and aryl groups a useful reaction in organic synthesis. Copper‐promoted conjugate additions were generally effected by allowing an organomagnesium reagent and a alpha, beta‐ unsaturated carbonyl compound to react in the presence of a catalytic amount of copper salt. Studies since 1966 have shown that stoichiometric organocopper reagents in addition to their broad utility in coupling reactions with organic halides and in reaction with other substrates undergo unusually effective conjugate addition to a wide variety alpha,beta‐ unsaturated carbonyl substrates. Emphasis in this chapter is on stoichiometric organic copper reagents. Mechanism, scope, limitations, synthetic utility, and optimal conditions are considered.

show abstract

Addition of methanol to hexynedioic esters. Synthesis of cyclopentanediones and muconates

Cited by 5 publications

References 4 publications

Pyrolysis studies of organic oxygenates. 5. Thermal chemistry pathways of 1-naphthol under hydrogen

Pyrolysis studies of organic oxygenates. 5. Thermal chemistry pathways of 1-naphthol under hydrogen

Formation of a stable Enol from a Michael addition

Conjugate Addition Reactions of Organocopper Reagents

Contact Info

Product

Resources

About