Efficient Preparation of Apically Substituted Diamondoid Derivatives

We present an effective three-step chromatography-free sequence for the preparation of apical monohydroxy derivatives of diamantane, triamantane, and [121]tetramantane from the corresponding bis-apical diols utilizing tert -butyldimethylsilyl chloride as the monosilylating agent. The procedure was successfully applied to the monoprotection of several other aliphatic and aromatic diols. Additionally, 9-aminodiamantan-4-carboxylic acid, which has significant potential in medicinal and material sciences, was prepared through Ritter reaction of 4,9-dihydroxydiamantane in trifluoroacetic acid.