Michael addition of nitroalkanes to nonactivated α,β-unsaturated δ-thiolactams: reactivity, diastereoselectivity, and comparison to α,β-unsaturated δ-lactams
作者:Jacek G. Sośnicki
DOI:10.1016/j.tet.2008.12.037
日期:2009.2
Aliphatic nitrocompounds add to nonactivated α,β-unsaturatedδ-thiolactams leading to 4-nitroalkyl functionalized δ-thiolactams in good yields. The addition is a stereocontrolled process with respect to substituents at C-6, and takes place producing trans 4,6-disubstituted adducts in most cases. Ease of the addition has been studied in relation to the structure of the δ-thiolactam acceptors, within
An easy approach to α,β-unsaturated δ-thiolactams via a RCM and thionation one-pot procedure
作者:Jacek G. Sośnicki
DOI:10.1016/j.tetlet.2008.10.113
日期:2009.1
An easy approach to mono- and bicyclic derivatives of 5,6-dihydro-1H-pyridine-2-thione via a one-pot ring closing metathesis (RCM) of dialkenoic amides and thionation using Lawesson’s reagent, followed by isomerization of the 3,6-dihydro-isomer (if necessary), is described. The appreciable differences in the reactivity of diallylic amides in RCM reactions are discussed.
New Stereoselective Synthesisof 2-Allyl-4-nitroalkylpiperidine-2-thiones and their Transformationto Annulated Piperidinones
作者:Jacek G. Sośnicki
DOI:10.1055/s-2003-41016
日期:——
Highly stereocontrolled access to trans-3-allyl-4nitro-alkyl-1,6-disubstituted δ-thiolactamswas achieved starting from piperidine-2-thione or commercially available2-mercaptopyridine via Michael-addition of nitroalkanes to 5,6-dihydropyridin-2-thiones,S-allylation and thio-Claisen rearrangement. The corresponding lactamsobtained by desulfurisation, were found to be suitable precursorsfor the construction of trans-fused bicyclic2-piperidinone derivatives (octahydro[2]pyrindinones)in a regio- and stereoselective radical 5-exo-trig annulationprocess.