2- Adamantanol oxidation

This dry ozonation procedure is a general method for hydrox-ylation of tertiary carbon atoms in saturated compounds (Table 1). The substitution reaction occurs with predominant retention of configuration. Thus cis-decalin gives the cis-l-decalol, whereas cis- and frans-l,4-dimethylcyclohexane afford cis- and trans-1,4-dimethylcyclohexanol, respectively. The amount of epimeric alcohol formed in these ozonation reactions is usually less than 1%. The tertiary alcohols may be further oxidized to diols by repeating the ozonation however, the yields in these reactions are poorer. For instance, 1-adamantanol is oxidized to 1,3-adamantane-diol in 43% yield. Secondary alcohols are converted to the corresponding ketone. This method has been employed for the hydroxylation of tertiary positions in saturated acetates and bromides. 

Adamantanol has been prepared by oxidation of adamantane with peroxyacetic acetic" and by hydrolysis of 1-bromoadamantane with silver nitrate s or hydrochloric acid. ... 

Carbonylation-oxidation of the THF complexes (S)-58 and (R)-58 afforded the optically active (3 )-(+)-2-methyl-l-adamantanol (3)-60 and (R)-(—)-2-methyl-l-adamantanol (R)-60, respectively (Scheme 24) <2003MC121, B-2003MI97>. 

It has been also found that PhIO as an oxidant in the presence of a catalytic amount of sulfonated manganese and iron porphyrin supported on poly(vinylpyridinium) polymers in olefin epoxidation and alkane hydroxylation is a better oxidant than Bu4NHS05 °. Oxidation of adamantane to 1-adamantanol in good yield using BU4NHSO5 and acetone in the presence of aqueous NaHCOs was also reported . ... 

Disubstituted adamantanes are most frequently obtained from internal cyclization reactions of a bridgehead substituent. Thus, photolysis of the azido-formate 79 gives 80 by nitrene insertion 279). 80 may be readily hydrolyzed to 2-amino-1-adamantanol (81) 75 Subsequent oxidation gives l-hydroxy-2-ada-mantanone (82) from which other derivatives may be prepared 280>2S1). An analogous carbene insertion is initiated by the thermal decomposition of the... 

Adamantane 205 reacts with oxaziridine 206 at 22°C to give 1-adamantanol 207 in 73% yield <2005JA15391>. A catalytic version of this oxidation has been developed using catalytic amounts of the imine 208 and diselenide 209 with excess urea-H202 (UHP) as the oxidant. 

Initially, Swem et al. reported the oxidation of sterically hindered alcohols to carbonyls with a dimethyl sulfoxide-trifluoroacetic anhydride complex.7 These reactants included primary alcohols such as 2,2-dimethyl-l-phenyl-propanol 3 and secondary alcohols, for example, 2-adamantanol 4. 

The allotropic form of oxygen, ozone, can also be employed for the oxidation of saturated hydrocarbons. The reactivity of ozone without additional reagents is not sufficient for the preparative functionalization of alkanes in solution however, its reactivity is increased substantially by the addition of iron(III) chloride [6] or antimony pentafluo-ride. [7] The dry ozonation variant [8] of Mazur et al. [9] by which alkanes are hydroxy-lated at tertiary C atoms with high selectivities and yields, was shown to be especially useful. According to this method, silica gel is coated with roughly 1 wt% of the substrate, cooled to -78 °C, saturated with ozone, and subsequently allowed to warm to room temperature within 0.5-2 h. Adamantane (1) is converted almost quantitatively into 1-adamantanol (4) in this way (Table 1), and this method of oxy-functionalization has been applied successfully even on certain steroids. [10]... 

Trialkylboranes give trialkylcarbinols on Hilmann carbonylation followed by oxidation . One of the most effective applications of this reaction in organic synthesis is the conversion of 1-boraadamantanes to the corresponding 1-adamantanols (Scheme 45) <76IZV2302>. 

Heteropolyanions have been shown to effectively catalyze the oxidation of alkanes into the corresponding alcohols and ketones [32], Thus, the compound [PW9037][Fe2Ni(0Ac)3] catalyzes [32b] the transformation ofadamantane into 1-adamantanol (76%), 2-adamantanol (12%) and 2-adamantanone (12%) with a total turnover number of 25 and a 29% conversion. The mixed-addenda hetero-... 

In a typical preparative scale experiment adamantane (1 gram) was oxidized with a CCbF solution of ozone at —78°C. for 8 days. After working up by the usual method, the residue was dissolved in ether and washed with aqueous sodium hydroxide. The ether layer on evaporation yielded a white crystalline solid (870 mg.). Elution with light petroleum (b.p., 30-40°C.) from neutral alumina (175 grams) gave unchanged adamantane (505 mg.), and 30% diethyl ether in petroleum eluted a ketonic fraction (63 mg.). Finally, pure ether eluted 1-adamantanol (227 mg.). TLC of the ketonic fraction separated the major component—adamantanone— from a minor unidentified component. 

Oxidation of C-H bonds. Carbonyl compounds are obtained from alcohols by oxidation with aq.H Oj-MTO. Some hydrocarbons are also oxidized adamantane to 1-adamantanol (88%), cii-decalin to ciy-4a-decalol (90%), and trany-decalin to trany-4a-decalol (20%). 

At —40°C and under Ar, (43c) reacts with adamantane to afford 1-adamantanol (56%) and 2-adamantanone (20%). With H2O2 as a terminal oxidant, however, (43a) and its sterically more demanding analogue [Fe(6-Me2-BPMCN)(OTf)2] (44a) catalyzes enantioselective epoxidation and ci5-dihydroxylation of alkene substrates, demonstrating the metal-based nature of this transformation. Apparently, the use of HOOH vs. ROOH significantly alters the pathways adopted by the Fe —OOR (R = alkyl or H) adduct. The origin of such a functional shift needs further clarification. 

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