The electron donor is added directly to the mixture of {TAIL ~ the titanium halide} and {HEAD ~ the olefin} 
The electron donor is added directly to the mixture of { TAIL ~ the titanium halide } and { HEAD ~ the olefin }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD