Studies On The First Total Synthesis Of Standishinal

Standishinal is one of tricyclic-diterpenes possessing the uncommon 1, 1, 4a-trimethylhydrofluorene skeleton. Standishinal possesses cytotoxic and aromatase inhibitory activities. Till now, no synthesis of standishinal has been reported. In attempt to synthesize standishinal, the following phenomenon were observed:1. Alkyloxybenzenes could be transformed into corresponding phenol at 25℃in the presence of MSA/P₂O₅ or MSA under solvent free condition. But Alkyloxybenzenes are stable in presence of MSA/P₂O₅ or MSA in CH₃NO₂ even at 80℃.2. Friedel-Crafts acylation of alkyloxybenzenes and p-bromophenol withα-cyclogeranic acid could not be realized under catalysis of MSA/P₂O₅, MSA or PPA in CH₃NO₂, or under catalysis of BF₃·Et₂O without CH₃NO₂.3. The reaction of 4-bromaophenol and geranic acid in the presecnce of p-TsOH afforded 4-bromophenolα-cyclogeranoate in which cyclization of geranic acid toα-cyclogeranic acid was followed by esterification ofα-cyclogeranic acid with p-bromophenol.