[3 + 4] ANNULATION USING A [a-(TRIMETHYLSILYL)ACRYLOYL]SILANE AND THE LITHIUM ENOLATE OF AN b,b-UNSATURATED METHYL KETONE: (1R,6S,7S)-4-(tert-BUTYLDIMETHYLSILOXY)-6-(TRIMETHYLSILYL)BICYCLO[5.4.0]UNDEC-4-EN-2-ONE

1999 ◽  
Vol 76 ◽  
pp. 199 ◽  
1990 ◽  
Vol 43 (8) ◽  
pp. 1375 ◽  
Author(s):  
RJ Dancer ◽  
RK Haynes ◽  
WA Loughlin ◽  
SC Vonwiller

Tandem conjugate addition-ring closure involving reaction of the lithium enolate arising from conjugate addition of lithiated (E)-but-2- enyldiphenylphosphine oxide to 2-methyl-cyclopent-2-enone with two moles of t-butylthioacrylate generates a hydrindanol, and, in the presence of copper(I), a lactone derived from the hydrindanol. β-Sulfonylacrylate phenyl and t-butyl thioesters, β-chlorovinyl, β- sulfonyl- and β-sulfinyl-vinyl ketones react with the foregoing enolate, and with the enolate generated through conjugate addition of a methylcuprate to 2-methylcyclohexenone to give unsaturated 1,5-dicarbonyl compounds. The β-chlorovinyl ketones in particular react rapidly and in high yield. 2-Methylcyclohexenone has thereby been converted into a cis-dimethyl octalone; the conversion illustrates the effectiveness of β-chlorovinyl methyl ketone in the Robinson annelation. Reactions of the lithium enolate and titanium enol of 2,6- dimethylcyclohexanone with the β-substituted enones to give the corresponding unsaturated 1,5-dicarbonyl compounds and other products are also recorded.


1985 ◽  
Vol 292 (3) ◽  
pp. 319-324 ◽  
Author(s):  
Johann T.B.H. Jastrzebski ◽  
Gerard Van Koten ◽  
Martin J.N. Christophersen ◽  
Casper H. Stam

2007 ◽  
Vol 7 (10) ◽  
pp. 535-543
Author(s):  
K. V. Kurmanadha Rao ◽  
V. V. G. Krishnamurty ◽  
C. Venkata Rao
Keyword(s):  

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