ISSN:
0947-6539
Keywords:
allylsilanes
;
diastereoselective synthesis
;
bicycloalkanes
;
cycloadditions
;
enones
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The titanium tetrachloride promoted reaction of allylsilanes 1 with 1-acetylcyclohexene is shown to afford the silylbicyclo[4.3.0]nonanes 9 ([3 + 2] cycloaddition products) along with the 1-acetyl-2-allylcyclohexane 4 (Hosomi-Sakurai product). Here we report that systematic variation of the substituents at the silicon atom of 1 allows suppression of the classical Hosomi-Sakurai reaction in favor of the [3 + 2] cycloaddition. Cycloaddition of the allylsilanes 1 d, 1 i, and 1 k with 1-acetylcycloalkenes 10, containing a 5-, 6-, 7-, 8-, or 12-membered ring, gives rise to the corresponding silylbicyclo[n.3.0]alkanes 11 - 13. The cycloaddition of allyltriisopropylsilane (1 k) and 1-acetyl-2-methylcycloalkenes 15 provides silylbicyclo[n.3.0]alkanes 16 with two contiguous quaternary carbon centers. The stereochemistry of the silylbicyclo[n.3.0]alkanes 11 a - c and 14 is unambiguously determined by X-ray analysis and 13C NMR spectroscopy.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19970030409