2-Alkyl-3-cyclopentenones were prepared in moderate yields starting from tetrahydrothiopyran-4-one by the one-pot Ramberg–Bäcklund reaction of 6-alkyl-1,4-dioxa-8-thiaspiro[4.5]decane 8,8-dioxides, followed by acid catalyzed de-dioxolanation.
Trialkylamine-mediated intramolecular cyclization of pent-4-enoyl chlorides was studied. Substitution with a tertiary alkyl group at the 2-position gave cyclopent-2-en-1-ones, while substitution with an aromatic group gave enol esters, which were formed by O-acylation of initially formed 3-chlorocyclopentanones with ketenes.
Mn(III) acetate-mediated regioselective benzylation of various α,β-unsaturated and β-alkoxy-α,β-unsaturated ketones
作者:Cihangir Tanyeli、Devrim Özdemirhan
DOI:10.1016/j.tetlet.2003.08.001
日期:2003.9
We describe herein the results of manganese(III) acetate mediated alpha'-benzylation of various a,p-unsaturated and beta-alkoxy-alpha,beta-unsaturated ketones in moderate yields. (C) 2003 Elsevier Ltd. All rights reserved.
Liotta, Dennis; Saindane, Manohar; Monahan III, Robert, Synthetic Communications, 1986, vol. 16, # 12, p. 1461 - 1468
作者:Liotta, Dennis、Saindane, Manohar、Monahan III, Robert、Brothers, David、Fivush, Adam
DOI:——
日期:——
Regioselective synthesis of cyclopentenones from 4-thianone