Kornfeld’s ketone

The vinyl triflate of Kornfeld s ketone has been subjected to Heck reactions with methyl acrylate, methyl methacrylate, and methyl 3-(A-rerr-butoxycarbonyl-A-methyl)amino-2-methylenepropionate leading to a formal synthesis of lysergic acid [257], A similar Heck reaction between l-(phenylsulfonyl)indol-5-yl triflate and dehydroalanine methyl ester was described by this research group [258], Chloropyrazines undergo Heck couplings with both indole and 1-tosylindole, and these reactions are discussed in Chapter 10 (pyrazines) [259], Rajeswaran and Srinivasan described an interesting arylation of bromomethyl indole 240 with arenes [260]. Subsequent desulfurization and hydrolysis furnishes 2-arytmethylindoles 241. Bis-indole 242 was also prepared in this study. Aryl iodides couple with indole under basic conditions to afford 2-arylindoles [261]. 

Bur SK, Padwa A (2002) A Novel Sequential Aminodiene Diels-Alder Strategy for the Rapid Construction of Substituted Analogues of Kornfeld s Ketone. Org Lett 4 4135... 

Sec. alcohols, can be oxidized to ketones with Raney-Ni and a H -acceptor carbonyl groups and carbon double and triple bonds can be reduced with Raney-Ni and a H2-donor. The hydrogen adsorbed by the Ni may be sufficient for the reduction, so that the addition of a H2-donor is not necessary.—E Dihydrocholesterol refluxed with cyclohexanone as H2-acceptor in toluene in the presence of Raney-Ni with vigorous stirring for 24 hrs. —cholestanone. Y 80%.—Anisyli-dene-p-methoxyacetophenone and diethylcarbinol as H2-donor refluxed in toluene in the presence of Raney-Ni for 24 hrs. - >- l,3-bis-(p-methoxyphenyl)propane. Y 80%. (F. e. s. E. C. Kleiderer and E. C. Kornfeld, J. Org. Chem. 13, 455 (1948).)... 

By using a variant of Rawal s azadiene Diels-Alder cycloaddition chemistry [103,104], it was possible to synthesize several Kornfeld ketone analogues with substitution patterns that are difficult to otherwise obtain. Thus, heating a mixture of furan 280a and Rawal s diene (281) in CH3CN at reflux for 2h resulted in the formation of a 2 1-mixture of diastereomeric amines 282 that was immediately treated with HF at room temperature to unmask the enone 283 (Scheme 13.64) [105,106]. The crude reaction mixture was then heated at reflux in toluene for 30 min to effect... 

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