Претраживање
Приказ резултата 31-40 од 45
Fullerene bisadduct regioisomers containing an asymmetric diamide tether
(Oxford : Pergamon-Elsevier Science Ltd, 2017)
Four macrocyclic bis(pyrrolidino)fullerene regioisomers with e-edge, e-face, trans-4 and cis-2 addition patterns were synthesized from the corresponding monoadduct by Prato's cycloaddition in a yield of 50%, and fully ...
Synthesis and properties of bis(pyrrolidino)fullerenes bridged by a flexible alkyl-tether
(Oxford : Pergamon-Elsevier Science Ltd, 2015)
The one-pot bistycloaddition of alkyl-tethered diglycines to C-60 provided five series of bridged bis(pyrrolidino)fullerenes with good regioselectivity, giving mainly cis-2 and cis-3 products. An influence of the bridge ...
Fullerene bisadduct regioisomers containing an asymmetric diamide tether
(Oxford : Pergamon-Elsevier Science Ltd, 2017)
Four macrocyclic bis(pyrrolidino)fullerene regioisomers with e-edge, e-face, trans-4 and cis-2 addition patterns were synthesized from the corresponding monoadduct by Prato's cycloaddition in a yield of 50%, and fully ...
Acid-catalyzed rearrangement of some steroidal isoxazolidines
(Elsevier, 1999)
Acid-catalyzed reaction of the steroidal Δ 1 -unsaturated 3β,5β- epoxyimino compound 2 and Δ 3 -unsaturated 1β,5β-epoxyimino products 3 and 7, results in intramolecular rearrangement involving the N-CH 3 group to give the ...
Ferrous ion induced decomposition of alkyl hypochlorites
(Elsevier, 1981)
The decomposition of primary, secondary and tertiary alkyl hypochlorites induced by ferrous and other one-electron oxidizable metal ions leads to δ-chloro alcohols in yields of 34-76%. In decomposition of tertiary alkyl ...
5,10:13,14-Disecosteroids: novel modified steroids containing 10- and 9-membered rings
(Oxford : Pergamon-Elsevier Science Ltd, 2009)
In this paper a synthetic pathway to the modified 5,10:13,14-bisfragmentation cholestane derivatives 8-14 is described. The synthesis involves introduction of the 5α- and 14α-hydroxyl groups in the cholestane molecule and ...
Oxidative 10-membered ring expansion and contraction of stereoisomeric 1(10)-unsaturated and 1,10-epoxy-5-oxo-5,10-secosteroids induced by peracids
(Oxford : Pergamon-Elsevier Science Ltd, 2012)
The present study is concerned with the oxidative behaviour of unsaturated and epoxy 5-oxo-5,10-secosteroids in the presence of m-CPBA or TFAA-UHP as oxidants in order to investigate potential parameters controlling the ...
Reaction of silyl ketene acetals with epoxides: a new method for the synthesis of gamma-butanolides
(Oxford : Pergamon-Elsevier Science Ltd, 2004)
Titanium tetrachloride promoted reaction of silyl ketene acetals with epoxides, followed by acidic work-up, affords butanolides in moderate/good yields. With epihalohydrins the reaction is regioselective and occurs at the ...
Steroid template associated peptides: design, synthesis and 2D NMR characterization of a novel protected 18-Phe,19-Gly-containing steroidal compound
(Oxford : Pergamon-Elsevier Science Ltd, 2007)
We report herein the synthesis of a novel modified steroid with two rigidly positioned amino acids in C- and N-protected forms (Gly-OtBu and N-Fmoc-l-Phe) at the angular positions (C-18 methylamino group and C-19 carboxylic ...
2-Alkylidene-4-oxothiazolidine S-oxides: synthesis and stereochemistry
(Oxford : Pergamon-Elsevier Science Ltd, 2013)
A series of 5-unsubstituted and 5-substituted 2-alkylidene-4-oxothiazolidine-S-oxides were synthesized by the sulfur-oxidation with m-CPBA. The stereochemistry of 5-substituted sulfoxides was determined by means of NMR ...