A Regioselective Cyclohexannulation Procedure<i>via</i>Dienamine [4 + 2] Cycloaddition. Synthesis of Functionalised Decalins
作者:Roger L. Snowden、Simon M. Linder、Manfred Wüst
DOI:10.1002/hlca.19890720505
日期:1989.8.9
A regioselective cyclohexannulation procedure, whose key step involves the [4 + 2] cycloaddition of dienamines 12–24 with methyl acrylate, allows the conversion of cycloalkanones 1–11 to bicyclic dienoates 25 – 37. The chemistry of 26 is briefly examined and, in the context of organoleptic studies concerning functionalised 5,5,9-tri-methyldecalins, the transformation of 37 to ketones 44 and 46 as well
Compounds of general formula (I) ##STR1## wherein X ia a --CO.sub.2 H, --NH(OH)CHO or --CONHOH group; R.sub.1 is a cylcoalkyl, cycloalkenyl or non-aromatic heterocyclic ring containing up to 3 heteroatoms, any of which may be (i) substituted by one ore more substituents selected from C.sub.1 -C.sub.6 alkyl, C.sub.2 -C.sub.6 alkenyl, halo, cyano (--CN), --CO.sub.2 H, --CO.sub.2 R, --CONH.sub.2, --CONHR, --CON(R).sub.2, --OH, --OR, oxo-, --SH, --SR, --NHCOR, and --NHCO.sub.2 R wherein R is C.sub.1 -C.sub.6 alkyl or benzyl and/or (ii) fused to a cycloalky or heterocyclic ring; and R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are as defined in specification are matrix metalloproteinase inhibitors.
addition of secondary amines to α,β- or β,β-disubstituted α,β-unsaturated esters was efficiently achieved under high pressure (10-16 kbar) in protic solvents in the absence of any catalyst. The expected cumbersome β-aminesters bearing a tertiary amine directly connected to a quaternary carbon atom could be isolated in fair to good yields. By using α,β,δ,γ,-unsaturated esters (alkyl sorbate), the addition
The first catalytic asymmetric Wittig reaction is presented. Hydrogen-bond donors catalyze the [2+2] cycloaddition reaction between stabilized phosphorus ylides and 4-substituted cyclohexanones, breaking their symmetry plane and furnishing axially chiral olefins with moderate stereoselectivities. asymmetric catalysis - chirality - olefination - Wittig reaction - ylides
The hyperbaricaza-Michaeladdition of mono- and diamines on α,β-unsaturated β,β-disubstituted mono- and diesters has been studied. While in the case of monoester, this reaction provides a β-aminoester presenting a quaternarycenter, a direct and efficient access to diester or lactams featuring an azanorbornyl skeleton was obtained when starting from a diester, following an unprecedented double aza-Michael