Part I. The reaction between chiral acyl chlorides and trans -2-substituted-cyclohexanols proceeds diastereoselectively, i.e. produces mixtures of unequal amounts of diastereomers. We found for the first time that addition of pyridine or diisopropylethylamine accelerates the acylation, and unexpectedly for some substituents (RX) may completely invert its diastereoselectivity. These observations have been rationalized in terms of a stereoselective intramolecular assistance by the RX group to the acylation of the neighboring hydroxyl (\"bait-and-hook\" mechanism). A series of trans -2-substituted-cyclohexanols were synthesized and acylated with a racemic reagent in presence and absence of pyridine. The results showed that the presence of a nucleophilic group on the second carbon allowed for the preferred formation of one of the diastereomers in the absence of pyridine. However, in the presence of pyridine, the diastereoselectivity would inverse, and the reaction would favor the formation of the other diastereomer. To test the intramolecular acyl transfer hypothesis in detail a series of thioglucosides has been synthesized. Part II. The synthesized thioglucosides were tested as inhibitors of fungal glycosidases. Two compounds showed greater than 80% inhibition values in excess of the activity of β-D-glucosidases. More interestingly, the same compounds showed a marked enhancement of α-D-galactosidase activity by as much as 35%.
","abstract_html":"<p>Part I. The reaction between chiral acyl chlorides and trans -2-substituted-cyclohexanols proceeds diastereoselectively, i.e. produces mixtures of unequal amounts of diastereomers. We found for the first time that addition of pyridine or diisopropylethylamine accelerates the acylation, and unexpectedly for some substituents (RX) may completely invert its diastereoselectivity. These observations have been rationalized in terms of a stereoselective intramolecular assistance by the RX group to the acylation of the neighboring hydroxyl ("bait-and-hook" mechanism). A series of trans -2-substituted-cyclohexanols were synthesized and acylated with a racemic reagent in presence and absence of pyridine. The results showed that the presence of a nucleophilic group on the second carbon allowed for the preferred formation of one of the diastereomers in the absence of pyridine. However, in the presence of pyridine, the diastereoselectivity would inverse, and the reaction would favor the formation of the other diastereomer. To test the intramolecular acyl transfer hypothesis in detail a series of thioglucosides has been synthesized. Part II. The synthesized thioglucosides were tested as inhibitors of fungal glycosidases. Two compounds showed greater than 80% inhibition values in excess of the activity of β-D-glucosidases. More interestingly, the same compounds showed a marked enhancement of α-D-galactosidase activity by as much as 35%.</p>","abstract_has_math":false,"creators":["Samoshin, Andrey V."],"institution":null,"degree_name":"Master of Science (M.S.)","degree_level":"Thesis - Pacific Access Restricted","degree_discipline":"Chemistry","degree_department":null,"school":null,"contributors":["Andreas Franz"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-01-01T08:00:00Z","date_published":"2011-01-01T08:00:00Z","updated_at":"2026-07-24T05:36:09Z","subjects":["Organic chemistry","Pure sciences","Chemicals and Drugs","Chemistry","Medical Pharmacology","Medicinal-Pharmaceutical Chemistry","Medicine and Health Sciences","Pharmaceutical Preparations","Pharmacy and Pharmaceutical Sciences","Physical Sciences and Mathematics"],"languages":[],"rights":[],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["9781124933740"],"render_values":[{"text":"9781124933740","href":null,"code":true}]}]},"links":{"outbound_url":"https://scholarlycommons.pacific.edu/uop_etds/275","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Andreas Franz"]},{"key":"dc:creator","label":"Author","values":["Samoshin, Andrey V."]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2018-06-29T07:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Chemistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis - Pacific Access Restricted"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (M.S.)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Organic chemistry","Pure sciences","Chemicals and Drugs","Chemistry","Medical Pharmacology","Medicinal-Pharmaceutical Chemistry","Medicine and Health Sciences","Pharmaceutical Preparations","Pharmacy and Pharmaceutical Sciences","Physical Sciences and Mathematics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["9781124933740","https://scholarlycommons.pacific.edu/uop_etds/275"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Part I. The reaction between chiral acyl chlorides and trans -2-substituted-cyclohexanols proceeds diastereoselectively, i.e. produces mixtures of unequal amounts of diastereomers. We found for the first time that addition of pyridine or diisopropylethylamine accelerates the acylation, and unexpectedly for some substituents (RX) may completely invert its diastereoselectivity. These observations have been rationalized in terms of a stereoselective intramolecular assistance by the RX group to the acylation of the neighboring hydroxyl (\"bait-and-hook\" mechanism). A series of trans -2-substituted-cyclohexanols were synthesized and acylated with a racemic reagent in presence and absence of pyridine. The results showed that the presence of a nucleophilic group on the second carbon allowed for the preferred formation of one of the diastereomers in the absence of pyridine. However, in the presence of pyridine, the diastereoselectivity would inverse, and the reaction would favor the formation of the other diastereomer. To test the intramolecular acyl transfer hypothesis in detail a series of thioglucosides has been synthesized. Part II. The synthesized thioglucosides were tested as inhibitors of fungal glycosidases. Two compounds showed greater than 80% inhibition values in excess of the activity of β-D-glucosidases. More interestingly, the same compounds showed a marked enhancement of α-D-galactosidase activity by as much as 35%.
"]},{"key":"dc:source","label":"Dc Source","values":["121"]},{"key":"dc:title","label":"Title","values":["Diastereoselective acylation of trans-2-substituted-cyclohexanols and glycosidase inhibition studies"]}]}],"canonical_facts":{"dc:contributor":["Andreas Franz"],"dc:creator":["Samoshin, Andrey V."],"dc:date.available":["2018-06-29T07:00:00Z"],"dc:description.abstract":["Part I. The reaction between chiral acyl chlorides and trans -2-substituted-cyclohexanols proceeds diastereoselectively, i.e. produces mixtures of unequal amounts of diastereomers. We found for the first time that addition of pyridine or diisopropylethylamine accelerates the acylation, and unexpectedly for some substituents (RX) may completely invert its diastereoselectivity. These observations have been rationalized in terms of a stereoselective intramolecular assistance by the RX group to the acylation of the neighboring hydroxyl (\"bait-and-hook\" mechanism). A series of trans -2-substituted-cyclohexanols were synthesized and acylated with a racemic reagent in presence and absence of pyridine. The results showed that the presence of a nucleophilic group on the second carbon allowed for the preferred formation of one of the diastereomers in the absence of pyridine. However, in the presence of pyridine, the diastereoselectivity would inverse, and the reaction would favor the formation of the other diastereomer. To test the intramolecular acyl transfer hypothesis in detail a series of thioglucosides has been synthesized. Part II. The synthesized thioglucosides were tested as inhibitors of fungal glycosidases. Two compounds showed greater than 80% inhibition values in excess of the activity of β-D-glucosidases. More interestingly, the same compounds showed a marked enhancement of α-D-galactosidase activity by as much as 35%.
"],"dc:identifier":["9781124933740","https://scholarlycommons.pacific.edu/uop_etds/275"],"dc:rights":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:source":["121"],"dc:subject":["Organic chemistry","Pure sciences","Chemicals and Drugs","Chemistry","Medical Pharmacology","Medicinal-Pharmaceutical Chemistry","Medicine and Health Sciences","Pharmaceutical Preparations","Pharmacy and Pharmaceutical Sciences","Physical Sciences and Mathematics"],"dc:title":["Diastereoselective acylation of trans-2-substituted-cyclohexanols and glycosidase inhibition studies"],"thesis:degree_discipline":["Chemistry"],"thesis:degree_level":["Thesis - Pacific Access Restricted"],"thesis:degree_name":["Master of Science (M.S.)"]},"updated_at":"2026-07-24T05:36:09Z"}