Novel synthesis of (E)-1-iodo-1-trimethylgermyl-1-alkenes

ORGN 95

Narayan G. Bhat, nbhat@panam.edu, Department of Chemistry, University of Texas-Pan American, 1201 West University Drive, Edinburg, TX 78541 and Fatima J. Zapata, Chemistry, University of Texas-Pan American, 1201 West University Drive, Edinburg, TX 78541.
A highly diastereoselective synthesis of (E)-1-iodo-1-trimethylgermyl-1-alkenes via the hydroalumination of the corresponding 1-trimethylgermyl-1-alkynes with diisobutylaluminum hydride (DIBAL-H) in dichloromethane followed by iodination with iodine is presented. 1-Trimethylgermyl-1-alkynes (easily prepared by the deprotonation of the corresponding alkynes followed by germylation with trimethylgermyl bromide) smoothly undergo hydroalumination with DIBAL-H in dichloromethane at room temperature for 16 h.. The iodination of the resulting intermediates with iodine in tetrahydrofuran at 0 oC provides the corresponding (E)-1-iodo-1-trimethylgermyl-1-alkenes in good yields (72%-84%) and in high stereochemical purities (> 98%).