Reaction with alicyclic alcohols

A variety of functionalised spiro 1,2,4-trioxanes has been synthesised from allylic alcohols in a one-pot radical-initiated reaction with a thiophenol and molecular oxygen. The resultant hydroperoxide is trapped by an alicyclic ketone (Scheme 27). The 6-(phenylthiomethyl) group lends itself to further manipulation <040L3035>. 

There is now general agreement that Vilsmeier reactions with acetals, ketals, and the corresponding thio derivatives proceed by loss of a molecule of alcohol or thiol to give the reactive unsaturated ether or thioether with cyclic ketals the alcohol remains tethered, and may be chlorinated. The acetals and ketals are often more readily available than the unsaturated ethers, and yields of products are similar. A wide range of aliphatic and alicyclic acetals and ketals has been formylated the reaction can tolerate bulky groups at either end of the double bond, as is shown for compound 64 (Eq. 51). Products are isolated as iminium sails... 

Substitution of an alicyclic ring for one of the aromatic rings in the amino alcohols such as 32 or 39 produces a series of useful antispasmodic agents that have found some use in the treatment of the symptoms of Parkinson s disease. Mannich reaction of acetophenone with formaldehyde and piperidine affords the amino-ketone, 44a. Reaction of the ketone with cyclohexylmagnesium... 

Alcohols, reaction of isocyanates with, 224-225 Alcoholysis, 69 Alicyclic dianhydrides, 297 Alignment coating, for liquid crystal devices, 269-270 Aliphatic AA-BB-type polyamides, synthesis of, 164-173 Aliphatic AB-type polyamides, 173-180 Aliphatic acids, 60... 

An economical, practical, and environmentally acceptable procedure was elaborated for oxidative deprotection of trimethylsilyl ethers to their corresponding carbonyl compounds. The reaction proceeded in a solventless system, within a short period of time, and yields were good. On irradiation in a conventional microwave for 30 s, trimethylsilyl ether of benzyl alcohol in the presence of mont-morilonite KIO and finely grounded Fe(N03)3 9H2O gave rise to benzaldehyde in 95% yield. The applicability of this method was tested with several aromatic, alicyclic, and aliphatic trimethylsilyl ethers. Duration did not exceed 1 min, and yields were not lower than 80% (Mojtahedi et al. 1999). 

To increase the yields of the ring closure reactions, a new method was developed that was successfully applied for the synthesis of alicyclic fused systems of both the parent oxazolidine-2-thione and tetrahydro-1,3-oxazine-2-thione (85S1149). As an example, the synthesis of 2-thioxoperhydro-l,3-benzoxazine 103 is described. The dithiocarbamate 101, prepared from the amino alcohol 100, carbon disulfide and triethylamine, was treated with ethyl chloroformate in the presence of triethylamine, to give the thioxo derivative 103 via the transition state 102 (85S1149). In this way, the fused-skeleton thioxooxazines (91, X = S, 92) can be prepared with considerably higher yields (50-70%) than by the earlier methods (85S1149). 

Further examples of reactions of aliphatic and alicyclic polycarboxylic acids with sulfur ictra-fluoride or sulfur tetrafluoride/hydrogen fluoride are known.The reaction of aliphatic hydroxycarboxylic acids with sulfur tetrafluoride can give different products depending on the reaction conditions, the position of the hydroxy group, and the presence of other substituents. The main products from a-hydroxycarboxylic acids are trifluoroalkyl fluorosulfites, e.g. 19, which can be hydrolyzed quantitatively to the corresponding alcohols. ... 

Hydroxylatiott. Tertiary C—H bonds of alicyclic hydrocarbons are oxidized to the corresponding alcohols by p-nitroperbenzoic acid. Unlike the oxidation with trifluoroperacetic acid (7, 281-282), the reaction occurs regioselectively and with practically complete retention of configuration, and thus is comparable to dry ozonation (6,440). 

Although aliphatic and alicyclic hydrocarbons react with most sul-fonating agents, the reactions are not suitable for the preparation of the pure sulfonic acids. " Certain olefins react with sulfur dioxide-dloxane complex to give olefinic sulfonic acids In this way, cyclohexene is converted to l-cyclohexene-3-sulfonic acid, whereas with concentrated sulfuric acid in a mixture of acetic acid and acetic anhydride the main product is 2-hydroxycyclohexanesuIfonic acld. 1-Propene-l-sulfonic acid is obtained in low yield by the action of oleum on n- or isopxopyl alcohol. ... 

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