ISSN:
0947-3440
Keywords:
Sulfenes
;
[4 + 2] Cycloaddition
;
Cyclopentadiene
;
(+)-10-Camphorsulfonyl chloride
;
Sulfonyl cyclopentadienides
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The bulky sulfenes generated in situ from (+)-10-camphor-, 10-camphane-, and 2-methyl-2-phenylpropanesulfonyl chloride (1a-c) and Et3N can be trapped by cyclopentadiene to give the [4 + 2] cycloadducts 6a-c. The mixture of endo-6a and exo-6a (no other diastereomers) is formed by complete asymmetric induction. In MeCN solution additionally the 1,3-di- and 1,2,4-trisulfonylated cyclopentadienides 4a-c and 5a (X-ray analysis) + 5c were obtained. On acidification, 4a and 5a were transformed into the pentafulvenoid derivatives 8a, 9a, 10a. The reaction of (+)-10-camphorsulfonyl chloride (1a)/Et3N with 1,2,3,4-tetraphenylcyclopentadiene afforded the sulfonylated product 11a, with 2-methylcyclopentadiene 50% endo-12a (X-ray analysis) and 10% exo-12a. From cyclopentadiene and the more electrophilic cyanosulfene (2e) and mesylsulfene (2f, X = Me), generated in situ from cyanomethanesulfonyl chloride (1e)/Et3N and from mesyl chloride/Et3N, the [4 + 2] cycloadducts 6e and 6g were obtained. Similarly, methanedisulfonyl dichloride (1f, X = Cl)/Et3N afforded stereospecifically by two subsequent [4 + 2] cycloadditions the spirodisulfone 16 (X-ray analysis).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1995199512300
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