59078-46-5

Upstream product

• 96999-02-9 α-bromocyclopropanecarboxylic acid chloride 
• 70339-23-0 1-bromo-1-cyclobutanecarboxylic acid chloride 
• 100-52-7 benzaldehyde 
• 123674-87-3 6-cyclopropylidene-5-oxaspiro<2.3>hexan-4-one 
• 122889-56-9 spiro<5-carbomethoxy-4-methyl-7-oxabicyclo<2.2.1>hept-5-en-2-one-3,1'-cyclopropane> 
• 40052-11-7 2-bromo-3-methyl-but-2-enoyl chloride 
• 122889-55-8 spiro<5,6-dicarbomethoxy-4-methyl-7-oxabicyclo<2.2.1>hept-5-en-2-one-3,1'-cyclopropane> 

Relevant academic research and scientific papers

Selected Transformations of 6-Cyclopropylidene-5-oxaspirohexan-4-one, a Highly Strained Tricyclic β-Lactone

The title lactone 2 acylates a variety of amines including phenylalanine, sterically hindered alcohols, and phenols.With activated non-enolizable carbonyl compounds, bis-spiro 6-membered β-keto lactones are formed. Oxidative rearrangement of 2 affords bis

Studies Dealing with the Excited-State Behavior of Substituted 8-Oxabicyclooct-6-en-2-ones

A series of 8-oxabicyclooct-6-en-2-ones was prepared by the rhodium(II)-catalyzed cyclization-cycloaddition reaction of α-diazopentanedione with various alkynes.The photochemical behavior of these oxabicyclic enones was investigated.Both direct and sensitized photolysis cleanly results in a 1,3-acyl shift.A slower, secondary photoprocess involving intramolecular hydrogen atom transfer and intramolecular cycloaddition of the resulting ketene was also uncovered.The photobehavior of the closely related 9-oxabenzocycloheptene system was also examined.The initially formed 1,3-sigmatropic rearranged product was found to undergo a novel 1,4-methoxyl migration on extended photolysis.The photochemistry of the homologous 7-oxabicyclohepten-2-one was studied.The results obtained can be interpreted in terms of an initial Norrish type I cleavage.The resulting diradical either couples to give the 1,3-acyl shift product or undergoes bond fragmentation, giving products derived from a stepwise retro-Diels-Alder reaction.

LOW TEMPERATURE KETENE PREPARATIONS USING NITROSYLTETRACARBONYLCHROMIUM (-II) ANION

Methylene and cyclopropyl ketenes can be generated at -100 deg C by the dehalogenation of α-bromoacylhalides using nitrosyltetracarbonylchromium (-II) anion.This facilitates the trapping of these ketenes with more stable ketenes to give mixed ketene dimers.