Journal article

Publication year: 2007

Pages: 5689-5696

Journal: The Journal of Organic Chemistry

Volume number: 72

Issue number: 15

ISSN: 0022-3263

DOI Link: https://doi.org/10.1021/jo070653z

Publisher: American Chemical Society

Abstract: 

The reactivities of the cyclic ketones cycloheptanone, cyclodecanone,
and cycloundecanone with dimethylsulfoxonium methylide generated from
trimethylsulfoxonium iodide and base (NaH) were studied in diglyme at
130 °C. Oxiranes, which primarily form via the Corey reaction, lead to
ring expansions to give oxetanes and oxacyclopentanes when an excess of
dimethylsulfoxonium methylide is used. The Corey reaction is suppressed
in the presence of excess of base, and 1,3-terminal dienes form instead
(we term this reaction the Yurchenko diolefination). Our mechanistic
proposal involves the deprotonation of the betaine that forms after the
attack of dimethylsulfoxonium methylide on the carbonyl group of the
ketone. The key step of the diolefination reaction involves a
[2,3]-sigmatropic rearrangement of the ylide to a γ-unsaturated
sulfoxide with a barrier of 9.9 kcal/mol (ΔH₂₉₈,
MP2/cc-pVDZ, for the cycloheptane derivative). The elimination of
sulfenic acid from the γ-unsaturated sulfoxide in the terminal step of
the diolefination is associated with a higher barrier (17.3 kcal/mol)
but is strongly accelerated in the presence of base. The reactivity of
cyclic ketones in the Yurchenko reaction depends on the ring size;
medium-sized cyclodecanone is less reactive than either cycloheptanone
or cyclododecanone.

Harvard Citation style: Butova, E., Fokin, A. and Schreiner, P. (2007) Beyond the Corey Reaction:  One-Step Diolefination of Cyclic Ketones, The Journal of Organic Chemistry, 72(15), pp. 5689-5696. https://doi.org/10.1021/jo070653z

APA Citation style: Butova, E., Fokin, A., & Schreiner, P. (2007). Beyond the Corey Reaction:  One-Step Diolefination of Cyclic Ketones. The Journal of Organic Chemistry. 72(15), 5689-5696. https://doi.org/10.1021/jo070653z