Some of the minor products were isolated from the above reaction to gain a further understanding of their formation and to help determine the best way to purify the crude product. Their amounts varied with the source of starting material (I), suggesting that the minor products may arise from impurities in I. The most abundant side product (5%) is a colorless ketone C6Bre0, mp 185-188'dec. Structure IIIa, X= Rr, is proposed on the bssis ...