147151-51-7Relevant articles and documents
Synthesis of Bridgehead-Substituted Bicycloheptanes by Radical Cyclization
Della, Ernest W.,Knill, Andrew M.,Pigou, Paul E.
, p. 2110 - 2114 (2007/10/02)
A kinetic investigation shows that the rate of cyclization (kC) of the (4-methylenecyclohexyl)methyl radical 3 at 25 deg C is 4.4 x 102 s-1, which is considerably slower than that (2.3 x 105 s-1) of the parent 5-hexenyl radical.The energy of activation for the process 3 -> 4 is 12.8 kcal mol-1, which is in excellent agreement with theoretical values derived from force-field calculations.Ring-closure of appropriately substituted (4-methylenecyclohexyl)methyl radical precursors allows the synthesis of bicycloheptyl systems with useful functionality at the bridgehead to be achieved readily and in high yield.An interesting example is given of the application of an iodine-atom-transfer cyclization to the synthesis of a bicycloheptane functionalized at C7 and C1.
