Synthesis of 8 was accomplished using a similar approach to the method previously reported for 7 but started from 2quinolizidone. The synthetic material possessed the same GC fragmentation and retention time, thus confirming the carbon skeleton of the three new analogs, 4 -6 (Fig. ) . Compounds 3 and Compound 5 was hypothesized to be structurally similar to 3 but contains a quinolizidine ring rather than indolizidine. To confirm this, we attempted a total synthesis (Scheme 1), which began by carbodiimide coupling of 6-methyl-1-(piperidin-2-yl)hept-5-en-2-one (9) with diethylphosphonoacetic acid to yield 10 .