NotesFAQContact Us
Collection
Advanced
Search Tips
Peer reviewed Peer reviewed
Direct linkDirect link
ERIC Number: EJ918562
Record Type: Journal
Publication Date: 2010-Aug
Pages: 4
Abstractor: As Provided
Reference Count: 15
ISBN: N/A
ISSN: ISSN-0021-9584
Probing the Reactivity of Dimethylsulfoxonium Methylide with Conjugated and Nonconjugated Carbonyl Compounds: An Undergraduate Experiment Combining Synthesis, Spectral Analysis, and Mechanistic Discovery
Ciaccio, James A.; Guevara, Elena L.; Alam, Rabeka; D'agrosa, Christina D.
Journal of Chemical Education, v87 n8 p850-853 Aug 2010
We introduce students to dimethylsulfoxonium methylide (DMSY) epoxidation of aryl and nonconjugated aliphatic aldehydes and ketones without revealing that DMSY cyclopropanates enones by Michael-initiated ring closure (MIRC). Each student performs the reaction of DMSY with one of nine carbonyl compounds, including four enones, and then analyzes the [superscript 13]C NMR and IR spectra of their reaction product in comparison with spectra of their carbonyl substrate. The spectra of products from aryl and nonconjugated aldehydes and ketones show the expected absence of a carbonyl peak and the addition of two upfield [superscript 13]C peaks (indicating carbonyl epoxidation), whereas spectra of products from enones unexpectedly (to the student) display a carbonyl peak, no alkene [superscript 13]C peaks, and three (instead of two) additional upfield [superscript 13]C peaks. Identification of the latter products as cyclopropyl ketones leads to a discussion of conjugate addition and MIRC, and it stresses the avoidance of making false assumptions regarding the outcome of chemical reactions. (Contains 4 notes, 1 table, 1 scheme and 2 figures.)
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A