- Odorant substances
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New odoriferous compounds, particularly the compounds having the following formula: STR1 wherein R is an aliphatic residue having the formula STR2 wherein R1 is a C1-4 alkyl, C1-4 alkylidene or C2-4 alkenyl, the sum of the carbon atoms being in those residues from 2 to 5, m and n being equal to zero or 1, p being 1, 2 or 3 and the dotted lines representing one or two optional double bonds. The invention also relates to a method for the preparation of new di-ketones I: as well as the use of I as odoriferous compounds in odoriferous compositions, which are characterized by a certain proportion of compounds having the formula I.
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- Stereochemistry of 1,4-Addition of Nucleophiles to Ethyl Cyclohexylidenecyanoacetates
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The stereochemistry of 1,4-addition of several nucleophiles such as cyanide, sodium borohydride, and methylmagnesium iodide to three substituted ethyl cyclohexylidenecyanoacetates (1-3) has been determined.A higher preference for equatorial attack is observed in these compounds than in related cyclohexanones, which is considerably diminished by the use of aprotic polar solvents.The results do not show any appreciable contribution of product stability control, recently shown to be important for hydride reduction of cyclohexanones, and have been rationalized on thebasis of a six-center cyclic transition state in which steric factors play a dominant role.These compounds have also been reduced by catalytic hydrogenation (Pd/C), and, interestingly, with unhindered systems (1, 2) hydrogenation takes place more from the axial side (40-60percent) as compared to cyclohexanones.
- Nasipuri, Dhanonjoy,Sarkar, Ashis,Konar, Samir K.
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p. 2840 - 2845
(2007/10/02)
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