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1,3-Dipolar cycloaddition of diazoalkanes to racemic and optically active α-(diethoxyphosphoryl)vinyl p-tolyl sulfoxides: a new synthesis of 3-phosphorylpyrazoles and asymmetric synthesis of cyclopropanes

✍ Scribed by Wanda H. Midura; Jerzy A. Krysiak; Marian Mikolajczyk

Publisher
Elsevier Science
Year
1999
Tongue
French
Weight
737 KB
Volume
55
Category
Article
ISSN
0040-4020

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✦ Synopsis

Cycloaddition of diazomethane and ethyl diazoacetate to a-(diethoxyphosphoryl)vinyl p-tolyl sulfoxide la and its P-substituted analogues (Me, Ph) results in the formation of 3-phosphorylpyrazoles in high yield. The reaction of chiral (S)-(+tla with diphenyldiazomethane proceeds fYly diastereoselectively to give the corresponding cyclopropane (+)-6a with the (Sc, S,) configuration determined by X-ray diffraction analysis. Diazopropane reacts with (X)-(+)-la to give only one diastereoisomer of the pyrazoline cycloadduct (+)-2e which undergoes decomposition to the cyclopropane (+)-6b with preservation of configurational integrity.

📜 SIMILAR VOLUMES

ChemInform Abstract: 1,3-Dipolar Cycload
ChemInform Abstract: 1,3-Dipolar Cycloaddition of Diazoalkanes to Racemic and Optically Active α-(Diethoxyphosphoryl)vinyl p-Tolyl Sulfoxides: A New Synthesis of 3-Phosphorylpyrazoles and Asymmetric Synthesis of Cyclopropanes.
✍ Wanda H. Midura; Jerzy A. Krysiak; Marian Mikolajczyk 📂 Article 📅 2010 🏛 John Wiley and Sons ⚖ 33 KB 👁 2 views

## Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable v

Asymmetric cyclopropanation of chiral (1
Asymmetric cyclopropanation of chiral (1-dimethoxyphosphoryl-2-phenyl)vinyl p-tolyl sulfoxide: a new synthesis of enantiomerically pure 2-amino-3-phenyl-1-cyclopropane-phosphonic acid—a constrained analog of phaclofen
✍ Wanda H Midura; Marian Mikołajczyk 📂 Article 📅 2002 🏛 Elsevier Science 🌐 French ⚖ 292 KB

E-(S)-(1-Dimethoxyphosphoryl-2-phenyl)vinyl p-tolyl sulfoxide 3 was found to undergo cyclopropanation with sulfur ylides [dimethyl(oxo)sulfonium methylide, diphenyl sulfonium isopropylide and ethyl (dimethylsulfuranylidene)acetate (EDSA)] in a highly diastereoselective manner. The major diastereomer

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A novel method for the asymmetric synthesis of 4,4-disubstituted 2-cyclopentenones from optically active 1-chlorovinyl p-tolyl sulfoxides and its application to the asymmetric total synthesis of (+)-α-cuparenone
✍ Tsuyoshi Satoh; Masaaki Yoshida; Yasuhiro Takahashi; Hiroyuki Ota 📂 Article 📅 2003 🏛 Elsevier Science 🌐 English ⚖ 411 KB

Enantiomerically pure 1-chlorovinyl p-tolyl sulfoxides having two different substituents at the 2-position were synthesized from unsymmetrical ketones and (R)-(-)-chloromethyl p-tolyl sulfoxide in three steps. Treatment of the 1-chlorovinyl p-tolyl sulfoxides with cyanomethyllithium at -78°C to room