2-Cyclohexenones startg

M / rr-butyllithium in pentane added dropwise at —40° to a stirred slurry of Cul in THF, stirred for an additional 15 min, treated dropwise with HMPA, cooled to — 78°, a soln. of startg. cyclohexenone in the same solvent added, treated during 15 min with a soln. of diisobutylaluminium hydride in 1 1 THF/HMPA at —78°, stirred for 15 min, allowed to warm to —40°, Cul added, stirring continued at —40° for 10 min, treated with acetaldehyde, allowed to warm to room temp., then stirred for an additional 6 h product. Y 72%. F.e. and electrophiles s. A.R. Daniewski et al., Ann. Chem. 1988, 593. ... 

A soln. of 2-carbomethoxy-2-cyclohexenone in chloroform added during 25 min to a mixture of startg. p-ketoester and 0.47 eqs. CS2CO3 in the same solvent at room temp., 2.5 h later CS2CO3 removed, and the crude product refluxed with / -TsOH in benzene product. Y 70% (99.5% cis-cis isomer). Solvent effects and reaction mechanisms s. P. Deslongchamps, J.-F. Lavallee, Tetrahedron Letters 29, 5117-8 (1988) 14a-hydroxysteroids by sequential Michael addition-intramolecular aldol condensation s. ibid. 6033-6. 

Alkyl-2-cyclohexenones. 84.Ig. startg. m. in dry tetrahydrofuran added at -78° during 1.5 hrs. under Ng to a soln. of ca. 1 equivalent Li-diisopropylamide (prepared in situ from -butyl-Li and diisopropylamine), after 45 min. a soln. of allyl bromide in tetrahydrofuran added during 20 min., and allowed to warm to room temp, during 4 hrs. intermediate (Y ca. 98%) refluxed with LiAlH4 in... 

Startg. m. allowed to react with 2.2 equivalents Na in liq. NH3 and 1 equivalent ethanol, the resulting crude 1,4-dihydropyridine deriv. treated 3 hrs. at room temp, with 3 equivalents aq.-ethanolic NaOH, and the product obtained after deacetalization by aq. HCl at 45° 2-cyclohexenone deriv. Y 90%. S. Dani-S. Danishefsky and A. Nagel, Chem. Commun. 1972, 373, 374. 

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