The present invention is directed to a novel compound, but-2-enoic acid 1,2-dimethyl-butyl ester, and a method of improving, enhancing or modifying a fragrance formulation through the addition of an olfactory acceptable amount of but-2-enoic acid 1,2-dimethyl-butyl ester.
The paper describes a cooperative NHC (N‐heterocyclic carbene) and ruthenium‐based redox catalysis for the mild aerobic oxidative esterification of various aromatic and heteroaromatic aldehydes. The ruthenium(II) complex Ru(bpz)3(PF6)2 (bpz=2,2′‐bipyrazine) as catalyst is shown to be compatible with free NHCs. The NHC is used in these cascade reactions for the umpolung of the aldehyde to form the corresponding
Complete Diastereocontrol in Intramolecular 1,3-Dipolar Cycloadditions of 2-Substituted 5-Hexenyl and 5-Heptenyl Nitrones: Application to the Synthesis of the β-Lactam Antibiotic 1β-Methylthienamycin
作者:Michael E. Jung、Binh T. Vu
DOI:10.1021/jo952254m
日期:1996.1.1
3,6-disubstituted perhydrocyclopenta[c]isoxazoles has been investigated. An alkyl or aryl substituent at C2 completely controls the stereochemistry of the ring juncture and, in the case of the 5-heptenyl systems, also the stereochemistry of the 3-methyl group. Thus one stereocenter controls the formation of the other three to give a product with four contiguous stereocenters. The use of an ethylene
Stereoselective tandem radical cyclisations: Synthesis of isoiridomyrmecin
作者:Jeremy D Kilburn
DOI:10.1016/0040-4039(90)80106-v
日期:1990.1
Tandem radicalcyclisation of bromide (8b) led to bicyclic ketone (13), an intermediate in the synthesis of isoiridomyrmecin (14), demonstrating that highly stereoselective tandem cyclisations from acyclic precursors can be achieved if the precursor is suitably substituted.
The intramolecular 1,3-dipolar cycloaddition of silacarbonyl ylides derived from a silylene and unsaturated aldehydes tethered to unactivated olefinic or acetylenicdipolarophiles successfully proceeded to directly afford bicyclosilaoxolane derivatives in good yields.