Synthesis of the spiroacetal-containing anti-Helicobacter pylori agents CJ-12,954 and CJ-13,014

The first synthesis of the spiroacetal-containing anti-Helicobacter pylori agents ent-CJ-12,954 and ent-CJ-13,014 is reported based on the union of a heterocycle-activated spiroacetal-containing sulfone fragment with a phthalide-containing aldehyde fragment; comparison of the H-1 and C-13 NMR data, optical rotations and HPLC retention times of the synthetic compounds (3S, 2"S, 5"S, 7"S)-(1a) and (3S, 2"S, 5"R, 7"S)-(2a) and the (3R)-diastereomers (3R, 2"S, 5"S, 7"S)-(1b) and (3R, 2"S, 5"R, 7"S)-(2b) with the naturally occurring compounds established that the synthetic isomers ( 1a) and ( 2a) were in fact enantiomeric to the natural products CJ-12,954 and CJ-13,014.