Asymmetric synthesis of <i>trans</i>-4,5-disubstituted γ-butyrolactones involving a key allylboration step. First access to (−)-nicotlactone B and (−)-galbacin
作者:S. Henrion、A. Macé、M. M. Vallejos、T. Roisnel、B. Carboni、J. M. Villalgordo、F. Carreaux
DOI:10.1039/c8ob00101d
日期:——
An efficient asymmetric synthesis of trans-4,5-disubstituted γ-butyrolactones from aldehydes and enantioenriched γ-carbamate alkenylboronates is reported. The cornerstone of this strategy is the implementation of sequential [3,3]-allyl cyanate rearrangement/allylboration/nucleophilic addition/cyclisation reactions. Diverse γ-butyrolactones such as the flavouring compounds, (+)-trans-whiskey lactone
On the use of E-1-methoxymethoxybut-2-enyl(tri-n-butyl)stannane as a threo-selective, homo-enolate equivalent
作者:Andrew J. Pratt、Eric J. Thomas
DOI:10.1039/c39820001115
日期:——
(E)-1-Methoxymethoxybut-2-enyl(tri-n-butyl)stannane, readily available by addition of tri-n-butylstannyllithium to crotonaldehyde, and protection of the alcohol so formed using chloromethyl methyl ether, reacts on heating with aromatic and aliphatic aldehydes to give threo-4,5-disubstituted butyrolactones.