Matches in SemOpenAlex for { <https://semopenalex.org/work/W4256367051> ?p ?o ?g. }
Showing items 1 to 62 of
62
with 100 items per page.
- W4256367051 endingPage "54" @default.
- W4256367051 startingPage "35" @default.
- W4256367051 abstract "Abstract The α-oxoketene dithioacetals of general formula 1 (Scheme 2), undergo regioselective 1,2-addition with allyl anions to afford the corresponding carbinol acetals 6 in quantitative yields, which on treatment with BF3.Et2O in refluxing benzene yield the corresponding aromatic systems. The method has been shown to be widely applicable as exemplified by a large number of allyl anions (Scheme 3) reacting with α-oxoketene dithioacetals with wide structural variation. However, when 1 carry the α-substituent the intermediate carbinol acetals 14 (Scheme 4) follow, different path to yield the corresponding indenes 15 in good yields. The cinnamoylketene dithioacetals 16 react with allyl anions to afford the corresponding methylthiostilbenes 18 (Scheme 5), while the homologous dithioacetal 20 failed to yield the corresponding 1,4-biaryl-1,3-diene 22 (Scheme 6). This limitation was circumvented by reacting 23 with allyl anions to afford the corresponding stilbenes 24, dienes 25 and triene 26 respectively. The method was successfully extended for naphthoannelation. Thus naphthalenes 28 (Scheme 7) were prepared by reacting benzylmagnesium chloride with 1. In this case the reaction followed a sequential 1,4-and 1,2-addition mode and yielded the corresponding benzyl substituted naphthalenes. This problem was solved by reacting benzylmagnesium chloride with 8 to afford the corresponding naphthalenes 31 (Scheme 8) in excellent yields. Similarly the lithio derivatives derived from toluene followed 1,2-addition mode with 1 to afford the derived methylthionaphthalenes 39 (Scheme 9) in high yields. The other alkyl substituted naphthalenes 41,43 (Scheme 9), 45,47 (Scheme 10) were similarly prepared. Also 1 and β-oxodithioacetals 8 reacted with 1-naphthylmethylmagnesium chloride to afford the corresponding phenanthrenes 49 and 51 respectively in good yields. The method was extended to benzanthracene 56 (Scheme 11) synthesis successfully. The 2-naphthylmethyl magnesium chloride reacted in a sequential 1,4- and 1,2- fashion to afford the corresponding naphthylmethyl hydrocarbons 58 while it reacted with β-oxodithioacetals to give expected condensed aromatics 60, 61 and 62 (Scheme 12) in high yields. The 1-naphthylmethylmagnesium chloride also reacted with β-oxodithioacetals 23 to afford the corresponding styrylphenanthrenes 65, dienes 66 and triene 67 respectively in high yields. The intermediate 69 precursor in the synthesis of hexahelicine was also obtained by reacting 68 with 1-naphthylmethylmagnesium chloride (Scheme 13). The oxygenated benzylmagnesium halides reacted with 1 in 1,2-fashion (Scheme 14) with the exception of the formation of 79. Five fold excess of Reformatsky reagent reacted with 1 to afford the corresponding salicylates 82 (Scheme 15) in high yields. Similarly 84 (Scheme 16) was formed. Propargylmagnesium chloride also reacted with 1 with the participation of solvent methanol to afford the corresponding thioresorcinol dimethylethers 86 (Scheme 17) in high yields. However, intermolecular solvent participation did not occur with open chain α-oxoketene dithioacetals (Scheme 18) and the possible mechanism for this transformation is proposed (Scheme 19). The anion derived from aminocrotonate 97 (Scheme 20) reacted with 1 to afford the corresponding aminosubstituted aromatics 100. To prepare totally unsubstituted aromatics the allylanion was reacted with phenylthioacrolein 101 as exemplified by the synthesis of benzene 108a (Scheme 23), naphthalenes 109,110 and phenanthrene 111 (Scheme 24). In general our new method of aromatic annelation is a versatile, efficient and widely applicable for creating a large number of aromatics from easily accessible open chain precursors." @default.
- W4256367051 created "2022-05-12" @default.
- W4256367051 creator A5005187751 @default.
- W4256367051 creator A5034517583 @default.
- W4256367051 date "1994-01-01" @default.
- W4256367051 modified "2023-09-30" @default.
- W4256367051 title "α-Oxoketene Dithioacetals as Intermediates for Aromatic Annelation" @default.
- W4256367051 doi "https://doi.org/10.1080/10426509408545339" @default.
- W4256367051 hasPublicationYear "1994" @default.
- W4256367051 type Work @default.
- W4256367051 citedByCount "0" @default.
- W4256367051 crossrefType "journal-article" @default.
- W4256367051 hasAuthorship W4256367051A5005187751 @default.
- W4256367051 hasAuthorship W4256367051A5034517583 @default.
- W4256367051 hasConcept C134121241 @default.
- W4256367051 hasConcept C155647269 @default.
- W4256367051 hasConcept C161790260 @default.
- W4256367051 hasConcept C178790620 @default.
- W4256367051 hasConcept C185592680 @default.
- W4256367051 hasConcept C191897082 @default.
- W4256367051 hasConcept C192562407 @default.
- W4256367051 hasConcept C2777691172 @default.
- W4256367051 hasConcept C2778142098 @default.
- W4256367051 hasConcept C2778689049 @default.
- W4256367051 hasConcept C2778695967 @default.
- W4256367051 hasConcept C2780263894 @default.
- W4256367051 hasConcept C59759590 @default.
- W4256367051 hasConcept C7512685 @default.
- W4256367051 hasConceptScore W4256367051C134121241 @default.
- W4256367051 hasConceptScore W4256367051C155647269 @default.
- W4256367051 hasConceptScore W4256367051C161790260 @default.
- W4256367051 hasConceptScore W4256367051C178790620 @default.
- W4256367051 hasConceptScore W4256367051C185592680 @default.
- W4256367051 hasConceptScore W4256367051C191897082 @default.
- W4256367051 hasConceptScore W4256367051C192562407 @default.
- W4256367051 hasConceptScore W4256367051C2777691172 @default.
- W4256367051 hasConceptScore W4256367051C2778142098 @default.
- W4256367051 hasConceptScore W4256367051C2778689049 @default.
- W4256367051 hasConceptScore W4256367051C2778695967 @default.
- W4256367051 hasConceptScore W4256367051C2780263894 @default.
- W4256367051 hasConceptScore W4256367051C59759590 @default.
- W4256367051 hasConceptScore W4256367051C7512685 @default.
- W4256367051 hasIssue "1" @default.
- W4256367051 hasLocation W42563670511 @default.
- W4256367051 hasOpenAccess W4256367051 @default.
- W4256367051 hasPrimaryLocation W42563670511 @default.
- W4256367051 hasRelatedWork W1983530002 @default.
- W4256367051 hasRelatedWork W1984744703 @default.
- W4256367051 hasRelatedWork W1985868134 @default.
- W4256367051 hasRelatedWork W2017334769 @default.
- W4256367051 hasRelatedWork W2065594281 @default.
- W4256367051 hasRelatedWork W2097014657 @default.
- W4256367051 hasRelatedWork W2138308124 @default.
- W4256367051 hasRelatedWork W2951766199 @default.
- W4256367051 hasRelatedWork W2952490423 @default.
- W4256367051 hasRelatedWork W2472474610 @default.
- W4256367051 hasVolume "95" @default.
- W4256367051 isParatext "false" @default.
- W4256367051 isRetracted "false" @default.
- W4256367051 workType "article" @default.