A borohydride, as e.g. an alkaline earth metal or {TAIL ~ preferably an alkaline metal borohydride}, such as potassium or sodium borohydride, is {HEAD ~ the least preferred reducing agent} 
A borohydride , as e.g. an alkaline earth metal or { TAIL ~ preferably an alkaline metal borohydride } , such as potassium or sodium borohydride , is { HEAD ~ the least preferred reducing agent }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD