Treatment of gibberellic acid (1) and 13-O-methoxymethylgibberellic acid (2) with lithium diisopropylamide (LDA), and then with Li in liquid ammonia gave 3-hydroxy diacid 4 and 5, respectively. From the diacid 5, gibberellin A₅₅ (10) and gibberellin A₁ (12) were synthesized. Without LDA treatment prior to Li-liquid ammonia reduction, 1 gave diacid 8 from which gibberellin A₆₀ (14) and gibberelin A₅ (17) were synthesized.