The present invention is directed to a novel compound, but-2-enoic acid 1-ethyl-2-methyl-propyl 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-ethyl-2-methyl-propyl ester.
The behavior of 3,4-dimethyl-1-pentyn-3-ol (II) and 3-isopropyl-4-methyl-1-pentyn-3-ol (III) toward formicacid was investigated. The carbinols, as in the previous report, were chosen as model ones in which the tertiary carbon atom is adjacent to the carbon atom carrying the hydroxyl group. Both carbinols gave a significant quantity of the respective aldehydes. These aldehydes were easily isolated
Diphenylprolinol Silyl Ether Catalyzed Asymmetric Michael Reaction of Nitroalkanes and β,β-Disubstituted α,β-Unsaturated Aldehydes for the Construction of All-Carbon Quaternary Stereogenic Centers
作者:Yujiro Hayashi、Yuya Kawamoto、Masaki Honda、Daichi Okamura、Shigenobu Umemiya、Yuka Noguchi、Takasuke Mukaiyama、Itaru Sato
DOI:10.1002/chem.201403588
日期:2014.9.15
synthetic equivalent of the asymmetric Michael reaction of ethyl and acetyl substituents by means of radical denitration and Nef reaction, respectively. The short asymmetricsynthesis of (S)‐ethosuximide with a quaternary carbon center was accomplished by using the present asymmetric Michael reaction as the key step. The reaction mechanism that involves the E/Z isomerization of α,β‐unsaturated aldehydes
NHC-Catalyzed Cascade Reaction between β-Methyl Enals and Dienones for Quick Construction of Complex Multicyclic Lactones
作者:Jun Sun、Jun Xu、Guihua Nie、Zhichao Jin、Yonggui Robin Chi
DOI:10.1021/acs.orglett.0c00533
日期:2020.4.3
A NHC-promoted cascade reactionbetween β-methyl enal and dienone is developed for quick access to multicyclic lactone molecules bearing quaternary chiral carbon centers. Our study constitutes the first 1,6-addition of the acylazolium vinyl enolate γ-carbon via NHC catalysis and provides rapid access to complex lactone molecules that are otherwise difficult to prepare. The structurally sophisticated
Carbene-Catalyzed [4 + 2] Cycloadditions of Vinyl Enolate and (in Situ Generated) Imines for Enantioselective Synthesis of Quaternary α-Amino Phosphonates
作者:Jun Sun、Chengli Mou、Zhongyao Wang、Fangcheng He、Jian Wu、Yonggui Robin Chi
DOI:10.1021/acs.orglett.8b02707
日期:2018.9.21
A carbene-catalyzed enantioselectiveaddition of enals to five-membered cyclicimines is developed. The reaction gives chiral quaternary α-amino phosphonates bearing tetrasubstituted carbon centers with excellent enantioselectivities. The imine substrates can be generated in situ from the corresponding amines under an oxidative condition that is compatible with the carbene catalysis. Thus, a one-pot