Cleavage of tetrahydrofuran

What product would you expect from cleavage of tetrahydrofuran with HI ... 

Orthophosphoric acid of 95% concentration is most efficient for effecting cleavage of tetrahydrofuran. Commercial orthophosphoric acid (85%) may be used however, the yield drops to 82% and approximately 10% of the tetrahydrofuran is recovered. Anhydrous orthophosphoric acid and tetraphosphoric acid cannot be employed conveniently because of the limited solubility of hydrogen iodide in these reagents. 

Carbomethoxybenzaldehyde, 100 Carbon disulfide, 57 Chlorine, 24 Chloroacetamide, 22 Chloroacetonitrile, 22 Chlorobenzene, 96 lra i-2-CHLOROCYCLOPENTANOL, 24 2-Chloroethyl benzoate, 11 Chloromethylation, 68 1-Chloromethylnaphthalene, 67, 68 Chlorourea, see Monochlorourea Choline, chloride benzoate, 10 Choline, iodide benzoate, 10 Cinnamaldehyde, 75, 77 Cleavage of tetrahydrofuran, 27, 33 Condensation, of aniline and triphenyl carbinol, 5... 

The cleavage of tetrahydrofuran and its alkylated derivatives with halogen acids is an excellent method for the preparation of, A-dihalo-alkanes.The reaction of tetrahydrofuran with the less-reactive hydrogen chloride stops at the chlorohydrin stage, whereas the reaction in the presence of zinc chloride catalyst leads to the formation of the dichloride. The crude reaction mixture containing the intermediate chlorohydrin may be treated directly with phosphorus tribromide, yielding tetramethylene chlorobromide. The preparation of dibromides can be accomplished easily with hydrogen bromide or phosphorus and bromine and diiodides, by the action of potassium iodide and orthophosphoric acid. ... 

Cleavage of tetrahydrofuran and its derivatives with other reagents has been carried out—acid halides lead to 4-halobutyl esters and phosphorus oxychloride to chloro ethers. - ... 

Therefore, our first idea was to 0-acylate simple enolates with phosgene. In a first course of attempts, we investigated the reaction of phosgene with alkaline metals enolates. For example we prepared lithium enolate of acetaldehyde through cleavage of tetrahydrofuran by n- butylllthium (Ref. 116) and reacted with phosgene under various conditions. Unfortunately, no trace of vinyl chloroformate was found in all experiments performed [Scheme 90]. 

The ether can be symmetrical or unsymraetrical, aliphatic, aromatic, or cyclic. The reaction can be of preparative value for example the cleavage of tetrahydrofurane with BzHe and L gives 4-iodobutane-l -ol in 90% yield. 

Ring opening of tetrahydrofuran to 4-iodobutanol was used as the starting point for a synthesis of the complex tetracyclic picrasane famework of triterpene quassinoids <050L5601>. Acylative cleavage of tetrahydrofuran can be performed under iodine-... 

Additional examples of synthetic application of periodic acid as an oxidant include the oxidative iodination of aromatic compounds [1336-1341], iodohydrin formation by treatment of alkenes with periodic acid and sodium bisulfate [1342], oxidative cleavage of protecting groups (e.g., cyclic acetals, oxathioacetals and dithioacetals) [1315, 1343], conversion of ketone and aldehyde oximes into the corresponding carbonyl compounds [1344], oxidative cleavage of tetrahydrofuran-substituted alcohols to -y-lactones in the presence of catalytic PCC [1345] and direct synthesis of nitriles from alcohols or aldehydes using HsIOe/KI in aqueous ammonia [1346],... 

Similarly, a 1 2 mixture of trimethylsilyldiethylarnine and allyl bromide will afford cleavage of tetrahydrofuran in toluene at 80-90°C for 12 h (eq 7). 

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