The bromination of methyl arteannuate (5) with NBS in CHCl~3 gave a mixture of 6 with another monobromo-compound which was obtained by TLC and HPLC (yield: 62%). The mixture was deuterized by NaBD~3CN or NaBD~4 in HMPA. From the product [15-H]-methyl arteannuate (6) was isolated and purified by TLC and HPLC (total yield: 13%). Its structure was determined by MS, and ^1H, ^2H and ^1^3C NMR. The ^1H NMR peak of 15-H of 6 is lower than that of 5. The other peaks of 5 and 6 are same. The ^1^3C NMR spectrum difference between 5 and 6 is characterized by 15-C peak. The chemical shift of peak of 6 is δ is 23.52 (t)ppm, and, that of 5, 23.72(q)ppm. The hydrolysis of 6 gave [15-H]-arteannuic acid (4) [m.p. 126-129℃, [α]~D^2^0 31.1ⅲ (c, 0.01, CHCl~3); 2: m.p. 130℃, [α]~D^2^8^.^5 31.3 (c, 0.0093, CHCl~3)^[^2^]] . [15-^3H]-arteannuic acid was also synthesized by the same method but using NaB^3H~4 instead of NaBD~4 as a tritiating agent (radioactivity yield: 12%; specific radioactivity: 10^8 dpm/mg).

Key words: CHEMICAL SYNTHESIS, ARTEANNUIC ACID, PRECURSOR, BIOSYNTHESIS, ARTEANNUIN, NUCLEAR MAGNETIC RESONANCE, MASS SPECTROGRAPHY, DEUTERIUM REAGENTS, BROMIDE, HYDROLYSIS