35115-45-8Relevant academic research and scientific papers
Tandem [4 + 2]/[3 + 2] Cycloadditions with Nitroethylene
Denmark, Scott E.,Hurd, Alexander R.
, p. 3045 - 3050 (2007/10/03)
The simplest nitroalkene, nitroethylene, undergoes Lewis acid-promoted [4 + 2] cycloaddition with chiral vinyl ethers to afford cyclic nitronates with high diastereoselectivity. The resulting cyclic nitronates react with electron deficient alkenes to effect a face selective [3 + 2] cycloaddition. The origin of stereocontrol in the [3 + 2] cycloaddition is due to the single ring substituent, a remote acetal center. The scope and limitations of the use of nitroethylene as a 4π component in Lewis acid-promoted cycloadditions are documented and discussed. Additionally, concise syntheses of the pyrrolizidine alkaloids (+)-macronecine and (+)-petasinecine are presented.
New chiral auxiliaries: Their use in the asymmetric hydrogenation of β-acetamidocrotonates
Potin,Dumas,d'Angelo
, p. 3483 - 3486 (2007/10/02)
Synthesis of chiral β-amido esters 7 with high diasteroisomeric excess was achieved by asymmetric hydrogenation (H2/PtO2) of stereogenic β-acetamidocrotonates 6 in which the chirality is present in the alkyl of the ester part. For such a purpose, new efficient chiral auxiliaries such as 2,2-diphenylcyclopentanol (12) and 1,1-diphenyl-3-methyl-2-butanol (13) were developed.
