Nitrenium Ion Azaspirocyclization-Spirodienone Cleavage: A New Synthetic Strategy for the Stereocontrolled Preparation of Highly Substituted Lactams and N-Hydroxy Lactams.
Saved in:
| Title: | Nitrenium Ion Azaspirocyclization-Spirodienone Cleavage: A New Synthetic Strategy for the Stereocontrolled Preparation of Highly Substituted Lactams and N-Hydroxy Lactams. |
|---|---|
| Authors: | Wardrop, Duncan J.1 wardropd@uic.edu, Burge, Matthew S.1 |
| Source: | Journal of Organic Chemistry. 12/9/2005, Vol. 70 Issue 25, p10271-10284. 14p. 6 Diagrams, 5 Charts. |
| Subjects: | Quinone, Chemistry, Ions, Lactams, Dimethyl sulfide, Sulfides, Atmospheric dimethyl sulfide |
| Abstract: | Although 1,4-cyclohexadienes 2, obtained through the Birch reduction of arenes 1, have found widespread use as masked β-oxo carbonyl synthons 3, the possibility that 2,5-cyclohexadienones 5 might also be employed to the same end has been overlooked despite their ready availability. As part of our ongoing investigation of the synthetic chemistry of nitrenium ions, we have developed a novel and efficient strategy for the stereoselective preparation of di- and trisubstituted azetidinone, pyrrolidinone, and piperidinone derivatives, which features the ozonolytic cleavage of azaspirocyclic 2,5-cyclohexadienones 12. For example, ozonolysis of spirodienone 12c in CH2Cl2 and reductive workup with dimethyl sulfide generated unstable β-formyl ester 21, whereas cleavage in MeOH followed by reduction with thiourea led to hemiaceta122. While both 21 and 22 partially decompose upon exposure to silica gel, they can be trapped in situ, with a variety of weakly basic nucleophiles, to usefully substituted products. The requisite spirodienone substrates are readily accessible through the nitrenium ion cyclization of alkyl ω-arylhydroxamates 10, which proceeds with moderate to high diastereoselectivity. [ABSTRACT FROM AUTHOR] |
| Copyright of Journal of Organic Chemistry is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
|---|---|
| Header | DbId: egs DbLabel: Engineering Source An: 19332621 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
| IllustrationInfo | |
| Items | – Name: Title Label: Title Group: Ti Data: Nitrenium Ion Azaspirocyclization-Spirodienone Cleavage: A New Synthetic Strategy for the Stereocontrolled Preparation of Highly Substituted Lactams and N-Hydroxy Lactams. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Wardrop%2C+Duncan+J%2E%22">Wardrop, Duncan J.</searchLink><relatesTo>1</relatesTo><i> wardropd@uic.edu</i><br /><searchLink fieldCode="AR" term="%22Burge%2C+Matthew+S%2E%22">Burge, Matthew S.</searchLink><relatesTo>1</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Organic+Chemistry%22">Journal of Organic Chemistry</searchLink>. 12/9/2005, Vol. 70 Issue 25, p10271-10284. 14p. 6 Diagrams, 5 Charts. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Quinone%22">Quinone</searchLink><br /><searchLink fieldCode="DE" term="%22Chemistry%22">Chemistry</searchLink><br /><searchLink fieldCode="DE" term="%22Ions%22">Ions</searchLink><br /><searchLink fieldCode="DE" term="%22Lactams%22">Lactams</searchLink><br /><searchLink fieldCode="DE" term="%22Dimethyl+sulfide%22">Dimethyl sulfide</searchLink><br /><searchLink fieldCode="DE" term="%22Sulfides%22">Sulfides</searchLink><br /><searchLink fieldCode="DE" term="%22Atmospheric+dimethyl+sulfide%22">Atmospheric dimethyl sulfide</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Although 1,4-cyclohexadienes 2, obtained through the Birch reduction of arenes 1, have found widespread use as masked β-oxo carbonyl synthons 3, the possibility that 2,5-cyclohexadienones 5 might also be employed to the same end has been overlooked despite their ready availability. As part of our ongoing investigation of the synthetic chemistry of nitrenium ions, we have developed a novel and efficient strategy for the stereoselective preparation of di- and trisubstituted azetidinone, pyrrolidinone, and piperidinone derivatives, which features the ozonolytic cleavage of azaspirocyclic 2,5-cyclohexadienones 12. For example, ozonolysis of spirodienone 12c in CH2Cl2 and reductive workup with dimethyl sulfide generated unstable β-formyl ester 21, whereas cleavage in MeOH followed by reduction with thiourea led to hemiaceta122. While both 21 and 22 partially decompose upon exposure to silica gel, they can be trapped in situ, with a variety of weakly basic nucleophiles, to usefully substituted products. The requisite spirodienone substrates are readily accessible through the nitrenium ion cyclization of alkyl ω-arylhydroxamates 10, which proceeds with moderate to high diastereoselectivity. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Journal of Organic Chemistry is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
| PLink | https://search.ebscohost.com/login.aspx?direct=true&site=eds-live&db=egs&AN=19332621 |
| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/jo051252r Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 14 StartPage: 10271 Subjects: – SubjectFull: Quinone Type: general – SubjectFull: Chemistry Type: general – SubjectFull: Ions Type: general – SubjectFull: Lactams Type: general – SubjectFull: Dimethyl sulfide Type: general – SubjectFull: Sulfides Type: general – SubjectFull: Atmospheric dimethyl sulfide Type: general Titles: – TitleFull: Nitrenium Ion Azaspirocyclization-Spirodienone Cleavage: A New Synthetic Strategy for the Stereocontrolled Preparation of Highly Substituted Lactams and N-Hydroxy Lactams. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Wardrop, Duncan J. – PersonEntity: Name: NameFull: Burge, Matthew S. IsPartOfRelationships: – BibEntity: Dates: – D: 09 M: 12 Text: 12/9/2005 Type: published Y: 2005 Identifiers: – Type: issn-print Value: 00223263 Numbering: – Type: volume Value: 70 – Type: issue Value: 25 Titles: – TitleFull: Journal of Organic Chemistry Type: main |
| ResultId | 1 |
