Ten alpha-santonin derivatives were synthesized in moderate to high yields. Four derivatives namely 10alpha-acetoxy-3-oxo-1,7alphaH,6,11betaH-guai-4-en-6,12-olide (2), isofotosantonic acid (3), 10alpha-hydroxy-3-oxo-1,7alphaH,6,11betaH-guai-4-en-6,12-olide (4), and lumisantonin (5), were prepared by