Organic reactions at high pressure. Wittig reaction of hindered ketones with nonstabilized ylides.
β Scribed by William G. Dauben; James J. Takasugi
- Publisher
- Elsevier Science
- Year
- 1987
- Tongue
- French
- Weight
- 190 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0040-4039
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β¦ Synopsis
The Wittig reaction between n-butylidenetriphenylphosphorane and a series of cyclohexanones of increasing steric hindrance around the carbonyl group has been studied at 7 kbar and 15 kbar pressure (0.75-1.5 GPa) and at 40 "C.
π SIMILAR VOLUMES
Volumes of activation have been obtained from rate measurements between 1 and 1000 bar of reactions between triphenyl-p-nitrobenzylidenephosphorane d
The Diels-Alder reaction of e-benzoquinone with substituted dienoic esters affords good yields of 4a,5,8,8a-tetrahydro-1,4+aphthalenediones, free from the isomeric hydroquinone. The reactions were conducted at room temperature under 15 kbar (1.5 GPa) pressure in dichloromethane solutions.
A series of hindered and/or labile alcohols has been derivatized with a variety of acylating and silylating agents using pyridine in methylene chloride at 15 kbar (1.5 GPa) pressure to afford excellent yields of protected alcohols at 20 "C, largely without the need for added DMAP. Methoxyethoxymeth