Of gibberellic acid

A 2-methoxyethoxymethyl ether was used to protect one phenol group during a total synthesis of gibberellic acid. 

A second route to the key tricyclic intermediate A for the synthesis of gibberellic acid was also developed (Ref. 8) ... 

Scheme 6. Corey s synthesis of gibberellic acid GA3 (22) employing the Upjohn catalytic dihydroxylation procedure.

In a synthesis of gibberellic acid, a diene and quinone, both with oxygen-substituted side chains, gave the initial intermediate. Later in the synthesis, an intramolecular D-A reaction was used to construct the A-ring. 

The preparation of a number of gibberellic acid amino-acid conjugates has also been described. ... 

Alkylation of the enolate of a carboxylic acid, formed as an intermediate in the Birch reduction of an aromatic acid, has been successfully exploited in synthesis, e.g., in the synthesis of gibberellic acid. A model compound 24 was reduced with sodium in diethyl ether-liquid ammonia and the resulting carbanion was alkylated with iodomethane to give 25 in ca. 80% yield87. 

BAS 111 l-Phenoxy-3-(lH-l,2,4-triazole-l-yl)-4-hydroxy-5,5-dimethylhexane [9003-11-6] (BAS 111) (46) is a triazole that has plant growth inhibiting properties. It exerts its influence by inhibiting the production of gibberellic acid in plants this has been demonstrated in canola (31,37). 

Gibberellic acid and (2,4-dichlorophenoxy) acetic acid increased the glycoside content of Omithogalum umbellatum, as measured by a biological assay of extracts. The active principle, strophanthidin, is one of the cardiac glycosides. 7 There is little reference in the literature to this type of work, but the hydrolytic effects of gibberellic acid on starch may shift the equilibrium toward phenyl glycoside formation in some plant species. 

One end of the lactone ring must be at position 1. This is apparent from the nuclear magnetic spectra of gibberellic acid and its derivatives (30). 

The infrared spectra of gibberellic acid and derivatives which all show absorption at ca. 1780 cm. 1 in solution, too high a frequency for the 8-lactone of the Japanese structure. 

Gibberellins which have a saturated ring A undergo epimerization at C-2 with dilute alkali at room temperature, presumably by a reversed aldol mechanism via intermediate (XXXIII) as first suggested by J. W. Comforth (3a). This epimerization has been shown to occur with gibberellin At and its methyl ester (XXXIV), with both C-8 epimeric tetrahydro derivatives of gibberellic acid and... 

Table II. Apparent Minimum Concentration of Gibberellic Acid-Like Substance in Higher Plants...

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