{"id":{"repo_id":"cent-lancashire","oai_identifier":"oai:clok.uclan.ac.uk:19968"},"canonical_url":"https://search.dev.ndltd.org/etd/cent-lancashire/oai:clok.uclan.ac.uk:19968","repository":{"repo_id":"cent-lancashire","name":"University of Central Lancashire","base_url":"https://clok.uclan.ac.uk/cgi/oai2"},"display":{"title":"Novel addition reactions of some benzopyrans","abstract":"Several chroman-4-ones were prepared by the pyrrolidine catalysed reaction of 2'-hydroxyacetophenone with carbonyl compounds. These were converted to 4-oxochroman-3-carbonitriles by a sequence of reactions which involved the preparation of 3-hydroxymethylenechroman-4-ones, their reaction with hydroxylamine to give benzopyrano[3,4-d]isoxazoles and base catalysed ring opening of the isoxazoles. The reaction of 2-isopropylchroman-4-one with ethyl formate yielded a rearrangement product, 3-(2-methylprop-l-enyl)chromone. The reaction of 2-cyclopropyl-2-methyl-3- hydroxymethylenechroman-4-one with hydroxylamine yielded 5-(2-hydroxyphenyl)-4-(4-hydroxy-1-methylbut-1-enyl)isoxazole as a major product. These difficulties limited the availability of benzopyrano[3,4-d]isoxazoles for the preparation of 4-oxochroman-3-carbonitriles. A new rearrangement was discovered which accompanies the reduction of 4-oxochroman-3-carbonitriles with sodium cyanoborohydride and yields of 2-amino-3-alkylchromones in admixture with 3-hydroxy-3-(2-hydroxyphenyl)-2- alkylpropanonitriles. Lithium dialkynylcuprates were prepared and were successfully added, in a 1,4-fashion, to chromone-3-carbonitrile yielding 2-(2-hydroxybenzoyl)-2-penten-4-ynonitriles. The addition of lithium dipent-1-ynylcuprate to chromone-3-carbonitrile gave a remarkable new compound Z-2-[6-propyl-8-oxo-6H,8H-bis[1]benzopyrano[2,3-b:3.4'e]pyridin-6-yl]oct-2-en-4-ynonitrile. The 1,4-addition of dialkynylcuprates to chromone-3-carboxaldehyde afforded 2-ethynyl-3-hydroxymethylenechroman-4-ones which suffered acid catalysed rearrangement to Z-2-hydroxy-3-(2-propynylidene)chroman-4-ones. Several chromones and coumarins bearing electronwithdrawing groups were prepared and gave high yields of 1,4-addition products with lithium bis(trimethylsilylethynyl)cuprate. -Alkynyllithiums gave mainly 1,2-addition products with chromone-3- carboxaldehyde in ether. 3-( 1 -Hydroxy-3-trimethylsilylprop-2-ynyl)chromone underwent an Ireland-Claisen rearrangement with triethyl orthoacetate yielding ethyl 5-(3-chromonyl)-3-trimethylsilyl-3,4-pentadienoate which rearranged further to give ethyl 5-(3-chromonyl)-3-trimethylsilyl-4-pentynoate. Besides the Ireland-Claisen rearrangement 3-(l-hydroxy-4,4-dimethylpent-2-ynyl)chromone also suffered an allylic Claisen rearrangement which afforded the byproduct ethyl 2-[2-Z-(4,4-dimethylpent-2-ynylidene)chroman-4-one]ethanoate. The phosphorus(Ill) esters of the chromonylpropargylic alcohols underwent facile rearrangement to chromones bearing allene functions in position 3. The Diels-Alder adducts of these allenylchromones with 4-methyl-1,2,4-triazoline-3,5-dione were prepared and characterised. 2-(Trimethylsilylethynyl)chromone-3-carboxaldehyde was obtained from 3-hydroxymethylene-2-(trimethylsilylethynyl)chroman-4-one by oxidation with triphenylcarbenium tetrafluoroborate. 1,2-Addition of lithium acetylides afforded mixtures of 2-trimethylsilylethynyl-3-( 1 -hydroxy-2-propynyl)chromones and the desilylated 2-ethynyl-3-( I -hydroxy-2-propynyl)chromones. 3-( 1 -Hydroxy-4,4-dimethylpent-2-ynyl)-2-(trimethylsilylethynyl)chromone was reacted with diethyl chlorophosphite giving diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-5,5-dimethyl- I ,2-pentadien-3-phosphonate. The reaction took a different course with 3-(1-hydroxy-3-phenylprop-2-ynyl)-2- ethynylchromone affording diethyl 2-[2-(3-phenylprop-2-ynyl)chromonyl]ethynylphosphite through an apparent [2,5] sigmatropic rearrangement. Diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-4,4-dimethyl- 1 ,2-pentadien-3-phosphonate underwent Myers cyclisation on heating affording diethyl 2,2-dimethyl-1 -(3-trimethylsilyl-4-xanthonyl)propanephosphonate, a new method of preparation of xanthones.","abstract_html":"Several chroman-4-ones were prepared by the pyrrolidine catalysed reaction of 2'-hydroxyacetophenone with carbonyl compounds. These were converted to 4-oxochroman-3-carbonitriles by a sequence of reactions which involved the preparation of 3-hydroxymethylenechroman-4-ones, their reaction with hydroxylamine to give benzopyrano[3,4-d]isoxazoles and base catalysed ring opening of the isoxazoles. The reaction of 2-isopropylchroman-4-one with ethyl formate yielded a rearrangement product, 3-(2-methylprop-l-enyl)chromone. The reaction of 2-cyclopropyl-2-methyl-3- hydroxymethylenechroman-4-one with hydroxylamine yielded 5-(2-hydroxyphenyl)-4-(4-hydroxy-1-methylbut-1-enyl)isoxazole as a major product. These difficulties limited the availability of benzopyrano[3,4-d]isoxazoles for the preparation of 4-oxochroman-3-carbonitriles. A new rearrangement was discovered which accompanies the reduction of 4-oxochroman-3-carbonitriles with sodium cyanoborohydride and yields of 2-amino-3-alkylchromones in admixture with 3-hydroxy-3-(2-hydroxyphenyl)-2- alkylpropanonitriles. Lithium dialkynylcuprates were prepared and were successfully added, in a 1,4-fashion, to chromone-3-carbonitrile yielding 2-(2-hydroxybenzoyl)-2-penten-4-ynonitriles. The addition of lithium dipent-1-ynylcuprate to chromone-3-carbonitrile gave a remarkable new compound Z-2-[6-propyl-8-oxo-6H,8H-bis[1]benzopyrano[2,3-b:3.4'e]pyridin-6-yl]oct-2-en-4-ynonitrile. The 1,4-addition of dialkynylcuprates to chromone-3-carboxaldehyde afforded 2-ethynyl-3-hydroxymethylenechroman-4-ones which suffered acid catalysed rearrangement to Z-2-hydroxy-3-(2-propynylidene)chroman-4-ones. Several chromones and coumarins bearing electronwithdrawing groups were prepared and gave high yields of 1,4-addition products with lithium bis(trimethylsilylethynyl)cuprate. -Alkynyllithiums gave mainly 1,2-addition products with chromone-3- carboxaldehyde in ether. 3-( 1 -Hydroxy-3-trimethylsilylprop-2-ynyl)chromone underwent an Ireland-Claisen rearrangement with triethyl orthoacetate yielding ethyl 5-(3-chromonyl)-3-trimethylsilyl-3,4-pentadienoate which rearranged further to give ethyl 5-(3-chromonyl)-3-trimethylsilyl-4-pentynoate. Besides the Ireland-Claisen rearrangement 3-(l-hydroxy-4,4-dimethylpent-2-ynyl)chromone also suffered an allylic Claisen rearrangement which afforded the byproduct ethyl 2-[2-Z-(4,4-dimethylpent-2-ynylidene)chroman-4-one]ethanoate. The phosphorus(Ill) esters of the chromonylpropargylic alcohols underwent facile rearrangement to chromones bearing allene functions in position 3. The Diels-Alder adducts of these allenylchromones with 4-methyl-1,2,4-triazoline-3,5-dione were prepared and characterised. 2-(Trimethylsilylethynyl)chromone-3-carboxaldehyde was obtained from 3-hydroxymethylene-2-(trimethylsilylethynyl)chroman-4-one by oxidation with triphenylcarbenium tetrafluoroborate. 1,2-Addition of lithium acetylides afforded mixtures of 2-trimethylsilylethynyl-3-( 1 -hydroxy-2-propynyl)chromones and the desilylated 2-ethynyl-3-( I -hydroxy-2-propynyl)chromones. 3-( 1 -Hydroxy-4,4-dimethylpent-2-ynyl)-2-(trimethylsilylethynyl)chromone was reacted with diethyl chlorophosphite giving diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-5,5-dimethyl- I ,2-pentadien-3-phosphonate. The reaction took a different course with 3-(1-hydroxy-3-phenylprop-2-ynyl)-2- ethynylchromone affording diethyl 2-[2-(3-phenylprop-2-ynyl)chromonyl]ethynylphosphite through an apparent [2,5] sigmatropic rearrangement. Diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-4,4-dimethyl- 1 ,2-pentadien-3-phosphonate underwent Myers cyclisation on heating affording diethyl 2,2-dimethyl-1 -(3-trimethylsilyl-4-xanthonyl)propanephosphonate, a new method of preparation of xanthones.","abstract_has_math":false,"creators":["Daia, Dan Eugen"],"institution":"University of Central Lancashire","degree_name":"phd","degree_level":"doctoral","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":1998,"date_issued":"1998-09","date_published":"1998-09","updated_at":"2026-07-24T01:36:03Z","subjects":["F100 - Chemistry"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Daia, Dan Eugen"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1998-09-01"]},{"key":"dc:date.issued","label":"Date","values":["1998-09"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["Chemistry"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Central Lancashire"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["https://knowledge.lancashire.ac.uk/id/eprint/19968/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["doctoral"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["phd"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["F100 - Chemistry"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://knowledge.lancashire.ac.uk/id/eprint/19968/1/19968%20Dan%20Eugen%20Daia%20Sep98%20novel%20addition%20reactions%20of%20some%20benzopy14ans%20degree%20of%20doctor%20of%20philosophy%20unpublished%20Sep98%20University%20of%20Central%20Lancashire%20chemistry%20336.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Several chroman-4-ones were prepared by the pyrrolidine catalysed reaction of 2'-hydroxyacetophenone with carbonyl compounds. These were converted to 4-oxochroman-3-carbonitriles by a sequence of reactions which involved the preparation of 3-hydroxymethylenechroman-4-ones, their reaction with hydroxylamine to give benzopyrano[3,4-d]isoxazoles and base catalysed ring opening of the isoxazoles. The reaction of 2-isopropylchroman-4-one with ethyl formate yielded a rearrangement product, 3-(2-methylprop-l-enyl)chromone. The reaction of 2-cyclopropyl-2-methyl-3- hydroxymethylenechroman-4-one with hydroxylamine yielded 5-(2-hydroxyphenyl)-4-(4-hydroxy-1-methylbut-1-enyl)isoxazole as a major product. These difficulties limited the availability of benzopyrano[3,4-d]isoxazoles for the preparation of 4-oxochroman-3-carbonitriles. A new rearrangement was discovered which accompanies the reduction of 4-oxochroman-3-carbonitriles with sodium cyanoborohydride and yields of 2-amino-3-alkylchromones in admixture with 3-hydroxy-3-(2-hydroxyphenyl)-2- alkylpropanonitriles. Lithium dialkynylcuprates were prepared and were successfully added, in a 1,4-fashion, to chromone-3-carbonitrile yielding 2-(2-hydroxybenzoyl)-2-penten-4-ynonitriles. The addition of lithium dipent-1-ynylcuprate to chromone-3-carbonitrile gave a remarkable new compound Z-2-[6-propyl-8-oxo-6H,8H-bis[1]benzopyrano[2,3-b:3.4'e]pyridin-6-yl]oct-2-en-4-ynonitrile. The 1,4-addition of dialkynylcuprates to chromone-3-carboxaldehyde afforded 2-ethynyl-3-hydroxymethylenechroman-4-ones which suffered acid catalysed rearrangement to Z-2-hydroxy-3-(2-propynylidene)chroman-4-ones. Several chromones and coumarins bearing electronwithdrawing groups were prepared and gave high yields of 1,4-addition products with lithium bis(trimethylsilylethynyl)cuprate. -Alkynyllithiums gave mainly 1,2-addition products with chromone-3- carboxaldehyde in ether. 3-( 1 -Hydroxy-3-trimethylsilylprop-2-ynyl)chromone underwent an Ireland-Claisen rearrangement with triethyl orthoacetate yielding ethyl 5-(3-chromonyl)-3-trimethylsilyl-3,4-pentadienoate which rearranged further to give ethyl 5-(3-chromonyl)-3-trimethylsilyl-4-pentynoate. Besides the Ireland-Claisen rearrangement 3-(l-hydroxy-4,4-dimethylpent-2-ynyl)chromone also suffered an allylic Claisen rearrangement which afforded the byproduct ethyl 2-[2-Z-(4,4-dimethylpent-2-ynylidene)chroman-4-one]ethanoate. The phosphorus(Ill) esters of the chromonylpropargylic alcohols underwent facile rearrangement to chromones bearing allene functions in position 3. The Diels-Alder adducts of these allenylchromones with 4-methyl-1,2,4-triazoline-3,5-dione were prepared and characterised. 2-(Trimethylsilylethynyl)chromone-3-carboxaldehyde was obtained from 3-hydroxymethylene-2-(trimethylsilylethynyl)chroman-4-one by oxidation with triphenylcarbenium tetrafluoroborate. 1,2-Addition of lithium acetylides afforded mixtures of 2-trimethylsilylethynyl-3-( 1 -hydroxy-2-propynyl)chromones and the desilylated 2-ethynyl-3-( I -hydroxy-2-propynyl)chromones. 3-( 1 -Hydroxy-4,4-dimethylpent-2-ynyl)-2-(trimethylsilylethynyl)chromone was reacted with diethyl chlorophosphite giving diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-5,5-dimethyl- I ,2-pentadien-3-phosphonate. The reaction took a different course with 3-(1-hydroxy-3-phenylprop-2-ynyl)-2- ethynylchromone affording diethyl 2-[2-(3-phenylprop-2-ynyl)chromonyl]ethynylphosphite through an apparent [2,5] sigmatropic rearrangement. Diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-4,4-dimethyl- 1 ,2-pentadien-3-phosphonate underwent Myers cyclisation on heating affording diethyl 2,2-dimethyl-1 -(3-trimethylsilyl-4-xanthonyl)propanephosphonate, a new method of preparation of xanthones."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Novel addition reactions of some benzopyrans"]}]}],"canonical_facts":{"dc:creator":["Daia, Dan Eugen"],"dc:date":["1998-09-01"],"dc:date.issued":["1998-09"],"dc:description.abstract":["Several chroman-4-ones were prepared by the pyrrolidine catalysed reaction of 2'-hydroxyacetophenone with carbonyl compounds. These were converted to 4-oxochroman-3-carbonitriles by a sequence of reactions which involved the preparation of 3-hydroxymethylenechroman-4-ones, their reaction with hydroxylamine to give benzopyrano[3,4-d]isoxazoles and base catalysed ring opening of the isoxazoles. The reaction of 2-isopropylchroman-4-one with ethyl formate yielded a rearrangement product, 3-(2-methylprop-l-enyl)chromone. The reaction of 2-cyclopropyl-2-methyl-3- hydroxymethylenechroman-4-one with hydroxylamine yielded 5-(2-hydroxyphenyl)-4-(4-hydroxy-1-methylbut-1-enyl)isoxazole as a major product. These difficulties limited the availability of benzopyrano[3,4-d]isoxazoles for the preparation of 4-oxochroman-3-carbonitriles. A new rearrangement was discovered which accompanies the reduction of 4-oxochroman-3-carbonitriles with sodium cyanoborohydride and yields of 2-amino-3-alkylchromones in admixture with 3-hydroxy-3-(2-hydroxyphenyl)-2- alkylpropanonitriles. Lithium dialkynylcuprates were prepared and were successfully added, in a 1,4-fashion, to chromone-3-carbonitrile yielding 2-(2-hydroxybenzoyl)-2-penten-4-ynonitriles. The addition of lithium dipent-1-ynylcuprate to chromone-3-carbonitrile gave a remarkable new compound Z-2-[6-propyl-8-oxo-6H,8H-bis[1]benzopyrano[2,3-b:3.4'e]pyridin-6-yl]oct-2-en-4-ynonitrile. The 1,4-addition of dialkynylcuprates to chromone-3-carboxaldehyde afforded 2-ethynyl-3-hydroxymethylenechroman-4-ones which suffered acid catalysed rearrangement to Z-2-hydroxy-3-(2-propynylidene)chroman-4-ones. Several chromones and coumarins bearing electronwithdrawing groups were prepared and gave high yields of 1,4-addition products with lithium bis(trimethylsilylethynyl)cuprate. -Alkynyllithiums gave mainly 1,2-addition products with chromone-3- carboxaldehyde in ether. 3-( 1 -Hydroxy-3-trimethylsilylprop-2-ynyl)chromone underwent an Ireland-Claisen rearrangement with triethyl orthoacetate yielding ethyl 5-(3-chromonyl)-3-trimethylsilyl-3,4-pentadienoate which rearranged further to give ethyl 5-(3-chromonyl)-3-trimethylsilyl-4-pentynoate. Besides the Ireland-Claisen rearrangement 3-(l-hydroxy-4,4-dimethylpent-2-ynyl)chromone also suffered an allylic Claisen rearrangement which afforded the byproduct ethyl 2-[2-Z-(4,4-dimethylpent-2-ynylidene)chroman-4-one]ethanoate. The phosphorus(Ill) esters of the chromonylpropargylic alcohols underwent facile rearrangement to chromones bearing allene functions in position 3. The Diels-Alder adducts of these allenylchromones with 4-methyl-1,2,4-triazoline-3,5-dione were prepared and characterised. 2-(Trimethylsilylethynyl)chromone-3-carboxaldehyde was obtained from 3-hydroxymethylene-2-(trimethylsilylethynyl)chroman-4-one by oxidation with triphenylcarbenium tetrafluoroborate. 1,2-Addition of lithium acetylides afforded mixtures of 2-trimethylsilylethynyl-3-( 1 -hydroxy-2-propynyl)chromones and the desilylated 2-ethynyl-3-( I -hydroxy-2-propynyl)chromones. 3-( 1 -Hydroxy-4,4-dimethylpent-2-ynyl)-2-(trimethylsilylethynyl)chromone was reacted with diethyl chlorophosphite giving diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-5,5-dimethyl- I ,2-pentadien-3-phosphonate. The reaction took a different course with 3-(1-hydroxy-3-phenylprop-2-ynyl)-2- ethynylchromone affording diethyl 2-[2-(3-phenylprop-2-ynyl)chromonyl]ethynylphosphite through an apparent [2,5] sigmatropic rearrangement. Diethyl 1-[3-(2-trimethylsilylethynyl)chromonyl]-4,4-dimethyl- 1 ,2-pentadien-3-phosphonate underwent Myers cyclisation on heating affording diethyl 2,2-dimethyl-1 -(3-trimethylsilyl-4-xanthonyl)propanephosphonate, a new method of preparation of xanthones."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://knowledge.lancashire.ac.uk/id/eprint/19968/1/19968%20Dan%20Eugen%20Daia%20Sep98%20novel%20addition%20reactions%20of%20some%20benzopy14ans%20degree%20of%20doctor%20of%20philosophy%20unpublished%20Sep98%20University%20of%20Central%20Lancashire%20chemistry%20336.pdf"],"dc:language":["en"],"dc:publisher.department":["Chemistry"],"dc:publisher.institution":["University of Central Lancashire"],"dc:relation.isreferencedby":["https://knowledge.lancashire.ac.uk/id/eprint/19968/"],"dc:subject":["F100 - Chemistry"],"dc:title":["Novel addition reactions of some benzopyrans"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T01:36:03Z"}