{"id":{"repo_id":"cent-lancashire","oai_identifier":"oai:clok.uclan.ac.uk:19267"},"canonical_url":"https://search.dev.ndltd.org/etd/cent-lancashire/oai:clok.uclan.ac.uk:19267","repository":{"repo_id":"cent-lancashire","name":"University of Central Lancashire","base_url":"https://clok.uclan.ac.uk/cgi/oai2"},"display":{"title":"Contributions to benzothiopyran chemistry","abstract":"A series of 2,3-dihydro-4H-[1]benzothiopyran-4-ones has been prepared by the cyclocondensation of a thiophenol with cz,13-unsaturated carboxylic acids in methanesuiphonic acid and selectively oxidised to their 1-oxides and 1,1-dioxides. Reduction and dehydration of the resulting benzothiopyran-4-ols gave the 2H-[1]benzothiopyrans and their 1-oxides and 1,1-dioxides, although the 1- oxides were more conveniently obtained by oxidation of the 2H- [1]benzothiopyrans. The influence of the oxidation state of the sulphur heteroatom on the reactivity of the thiopyran ring has been studied. Based on hydroboration studies and the behavior towards triazolinediones, 2H-[1]benzothiopyrans are more reactive than their oxidised counterparts. Novel 2,3-dihydro-4H-[ 1 ]benzothiopyran-3 ,4-diones have been synthesised and their chemistry investigated. Although in some instances the two carbonyl functions exhibit comparable reactivity, reaction with phosphorus ylides occurs regiospecifically at the 3-position. The use of excess ylide promoted an a-ketol rearrangement and gave a stabilised ylide which has been characterised by Xray crystallography. 2,3-Dihydro-4H-[1]benzothiopyran-3-ones, the synthesis of which has been greatly improved, have been converted into their 4-dimethylaminomethylene derivatives and these together with the 3,4-diones and the 2,3-dihydro-3-(hydroxymethylene)-4H-[l]benzothiopyran-4-ones have been used as biselectrophiles to prepare a range of 3,4-heteroannulated [l]benzothiopyrans. The new thiopyrano[2,3-c][ljbenzothiopyran ring system has been obtained by a one-pot thionation-hetero Diels-Alder reaction sequence from 2,3-dihydro-4-(dimethylaminomethylene)-4H-[1]benzothiopyran-3-one and a43-unsaturated aldehydes. The linear thiopyrano[3,2-b][l]benzothiopyran system has been similarly prepared from the 2-dimethylaminomethylene analogue. 6H, 1 2H-[ 1 ]Benzothiopyrano[3,4-b][ 1]benzopyran- 12-ones have been synthesised by 2-fluorobenzoylation of 3-pyrrolidino-2H-[ 1]benzothiopyTan and intramolecular cyclisation of the resulting diketones. Selective reduction of the a43-unsaturated carbonyl function has been achieved, providing a facile access to 5-thiorotenoids. Attemps to produce these thiorotenoids by the thermal condensation of ethoxycarbonyl derivatives of benzothiopyran-3-ones with 4- methoxyphenol failed, but gave instead the novel bis[lbenzothiopyrano[3,2- b:4,3-e]pyran ring system.","abstract_html":"A series of 2,3-dihydro-4H-[1]benzothiopyran-4-ones has been prepared by the cyclocondensation of a thiophenol with cz,13-unsaturated carboxylic acids in methanesuiphonic acid and selectively oxidised to their 1-oxides and 1,1-dioxides. Reduction and dehydration of the resulting benzothiopyran-4-ols gave the 2H-[1]benzothiopyrans and their 1-oxides and 1,1-dioxides, although the 1- oxides were more conveniently obtained by oxidation of the 2H- [1]benzothiopyrans. The influence of the oxidation state of the sulphur heteroatom on the reactivity of the thiopyran ring has been studied. Based on hydroboration studies and the behavior towards triazolinediones, 2H-[1]benzothiopyrans are more reactive than their oxidised counterparts. Novel 2,3-dihydro-4H-[ 1 ]benzothiopyran-3 ,4-diones have been synthesised and their chemistry investigated. Although in some instances the two carbonyl functions exhibit comparable reactivity, reaction with phosphorus ylides occurs regiospecifically at the 3-position. The use of excess ylide promoted an a-ketol rearrangement and gave a stabilised ylide which has been characterised by Xray crystallography. 2,3-Dihydro-4H-[1]benzothiopyran-3-ones, the synthesis of which has been greatly improved, have been converted into their 4-dimethylaminomethylene derivatives and these together with the 3,4-diones and the 2,3-dihydro-3-(hydroxymethylene)-4H-[l]benzothiopyran-4-ones have been used as biselectrophiles to prepare a range of 3,4-heteroannulated [l]benzothiopyrans. The new thiopyrano[2,3-c][ljbenzothiopyran ring system has been obtained by a one-pot thionation-hetero Diels-Alder reaction sequence from 2,3-dihydro-4-(dimethylaminomethylene)-4H-[1]benzothiopyran-3-one and a43-unsaturated aldehydes. The linear thiopyrano[3,2-b][l]benzothiopyran system has been similarly prepared from the 2-dimethylaminomethylene analogue. 6H, 1 2H-[ 1 ]Benzothiopyrano[3,4-b][ 1]benzopyran- 12-ones have been synthesised by 2-fluorobenzoylation of 3-pyrrolidino-2H-[ 1]benzothiopyTan and intramolecular cyclisation of the resulting diketones. Selective reduction of the a43-unsaturated carbonyl function has been achieved, providing a facile access to 5-thiorotenoids. Attemps to produce these thiorotenoids by the thermal condensation of ethoxycarbonyl derivatives of benzothiopyran-3-ones with 4- methoxyphenol failed, but gave instead the novel bis[lbenzothiopyrano[3,2- b:4,3-e]pyran ring system.","abstract_has_math":false,"creators":["Heron, Bernard Mark"],"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":1992,"date_issued":"1992-08","date_published":"1992-08","updated_at":"2026-07-24T01:36:00Z","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":["Heron, Bernard Mark"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["1992-08-01"]},{"key":"dc:date.issued","label":"Date","values":["1992-08"]},{"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/19267/"]},{"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/19267/1/19267%20Bernard%20Mark%20Heron%20Aug92%20contributions%20to%20benzothypyran%20chemistry%20%20Doctor%20of%20Philosophy%20unpublished%20Aug92%20University%20of%20Central%20Lancashire%20chemistry%20347.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["A series of 2,3-dihydro-4H-[1]benzothiopyran-4-ones has been prepared by the cyclocondensation of a thiophenol with cz,13-unsaturated carboxylic acids in methanesuiphonic acid and selectively oxidised to their 1-oxides and 1,1-dioxides. Reduction and dehydration of the resulting benzothiopyran-4-ols gave the 2H-[1]benzothiopyrans and their 1-oxides and 1,1-dioxides, although the 1- oxides were more conveniently obtained by oxidation of the 2H- [1]benzothiopyrans. The influence of the oxidation state of the sulphur heteroatom on the reactivity of the thiopyran ring has been studied. Based on hydroboration studies and the behavior towards triazolinediones, 2H-[1]benzothiopyrans are more reactive than their oxidised counterparts. Novel 2,3-dihydro-4H-[ 1 ]benzothiopyran-3 ,4-diones have been synthesised and their chemistry investigated. Although in some instances the two carbonyl functions exhibit comparable reactivity, reaction with phosphorus ylides occurs regiospecifically at the 3-position. The use of excess ylide promoted an a-ketol rearrangement and gave a stabilised ylide which has been characterised by Xray crystallography. 2,3-Dihydro-4H-[1]benzothiopyran-3-ones, the synthesis of which has been greatly improved, have been converted into their 4-dimethylaminomethylene derivatives and these together with the 3,4-diones and the 2,3-dihydro-3-(hydroxymethylene)-4H-[l]benzothiopyran-4-ones have been used as biselectrophiles to prepare a range of 3,4-heteroannulated [l]benzothiopyrans. The new thiopyrano[2,3-c][ljbenzothiopyran ring system has been obtained by a one-pot thionation-hetero Diels-Alder reaction sequence from 2,3-dihydro-4-(dimethylaminomethylene)-4H-[1]benzothiopyran-3-one and a43-unsaturated aldehydes. The linear thiopyrano[3,2-b][l]benzothiopyran system has been similarly prepared from the 2-dimethylaminomethylene analogue. 6H, 1 2H-[ 1 ]Benzothiopyrano[3,4-b][ 1]benzopyran- 12-ones have been synthesised by 2-fluorobenzoylation of 3-pyrrolidino-2H-[ 1]benzothiopyTan and intramolecular cyclisation of the resulting diketones. Selective reduction of the a43-unsaturated carbonyl function has been achieved, providing a facile access to 5-thiorotenoids. Attemps to produce these thiorotenoids by the thermal condensation of ethoxycarbonyl derivatives of benzothiopyran-3-ones with 4- methoxyphenol failed, but gave instead the novel bis[lbenzothiopyrano[3,2- b:4,3-e]pyran ring system."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Contributions to benzothiopyran chemistry"]}]}],"canonical_facts":{"dc:creator":["Heron, Bernard Mark"],"dc:date":["1992-08-01"],"dc:date.issued":["1992-08"],"dc:description.abstract":["A series of 2,3-dihydro-4H-[1]benzothiopyran-4-ones has been prepared by the cyclocondensation of a thiophenol with cz,13-unsaturated carboxylic acids in methanesuiphonic acid and selectively oxidised to their 1-oxides and 1,1-dioxides. Reduction and dehydration of the resulting benzothiopyran-4-ols gave the 2H-[1]benzothiopyrans and their 1-oxides and 1,1-dioxides, although the 1- oxides were more conveniently obtained by oxidation of the 2H- [1]benzothiopyrans. The influence of the oxidation state of the sulphur heteroatom on the reactivity of the thiopyran ring has been studied. Based on hydroboration studies and the behavior towards triazolinediones, 2H-[1]benzothiopyrans are more reactive than their oxidised counterparts. Novel 2,3-dihydro-4H-[ 1 ]benzothiopyran-3 ,4-diones have been synthesised and their chemistry investigated. Although in some instances the two carbonyl functions exhibit comparable reactivity, reaction with phosphorus ylides occurs regiospecifically at the 3-position. The use of excess ylide promoted an a-ketol rearrangement and gave a stabilised ylide which has been characterised by Xray crystallography. 2,3-Dihydro-4H-[1]benzothiopyran-3-ones, the synthesis of which has been greatly improved, have been converted into their 4-dimethylaminomethylene derivatives and these together with the 3,4-diones and the 2,3-dihydro-3-(hydroxymethylene)-4H-[l]benzothiopyran-4-ones have been used as biselectrophiles to prepare a range of 3,4-heteroannulated [l]benzothiopyrans. The new thiopyrano[2,3-c][ljbenzothiopyran ring system has been obtained by a one-pot thionation-hetero Diels-Alder reaction sequence from 2,3-dihydro-4-(dimethylaminomethylene)-4H-[1]benzothiopyran-3-one and a43-unsaturated aldehydes. The linear thiopyrano[3,2-b][l]benzothiopyran system has been similarly prepared from the 2-dimethylaminomethylene analogue. 6H, 1 2H-[ 1 ]Benzothiopyrano[3,4-b][ 1]benzopyran- 12-ones have been synthesised by 2-fluorobenzoylation of 3-pyrrolidino-2H-[ 1]benzothiopyTan and intramolecular cyclisation of the resulting diketones. Selective reduction of the a43-unsaturated carbonyl function has been achieved, providing a facile access to 5-thiorotenoids. Attemps to produce these thiorotenoids by the thermal condensation of ethoxycarbonyl derivatives of benzothiopyran-3-ones with 4- methoxyphenol failed, but gave instead the novel bis[lbenzothiopyrano[3,2- b:4,3-e]pyran ring system."],"dc:format":["application/pdf"],"dc:identifier.uri":["https://knowledge.lancashire.ac.uk/id/eprint/19267/1/19267%20Bernard%20Mark%20Heron%20Aug92%20contributions%20to%20benzothypyran%20chemistry%20%20Doctor%20of%20Philosophy%20unpublished%20Aug92%20University%20of%20Central%20Lancashire%20chemistry%20347.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/19267/"],"dc:subject":["F100 - Chemistry"],"dc:title":["Contributions to benzothiopyran chemistry"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["doctoral"],"dc:type.qualificationname":["phd"]},"updated_at":"2026-07-24T01:36:00Z"}