ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The conditions for the novel tandem Pauson-Khand reaction have been explored. The highly functionalized tetracyclic compounds 11c, 11d, and 16 were prepared from the ene-diynes 4c, 4d, and 10 by treatment with 2 equiv. of [Co2(CO)8] and 4-methylmorpholine N-oxide (NMO) or Me3NO in yields of 24, 22, and 53%, respectively (Table). In the presence of 1-3 equiv. of H2O added to the NMO used for induction of the Pauson-Khand reaction of 6d, a mixture of cyclopentanones 17/18 and cyclopentenones 12/13 was obtained (Scheme 5). The first example of a [Co2(CO)6]-induced highly stereoselective ene reaction is described. To account for these results, the formation of intermediates are proposed (Schemes 6 and 7) which hitherto have not been considered in the mechanistic description of the Pauson-Khand reaction.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19960790214
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