The symmetrical bis-cholestanyl pyrazine was also prepared as shown in Scheme II. Thus, treatment of azido ketone 3 with 0-met. hylhydroxy1amine provided the 0-methyloxime, which was reduced with triphenylphosphine in aqueous THF to obtain the 2-amino-3-oxime derivative of cholestane 5. This material was heated in toluene at 140 OC to obtain pyrazine 4 in about 77% overall yield from 3.
