Tetrahydrofuroic acid

Thus, reaction of tetrahydrofuroic acid (40-1) with triphenylphosphoryl azide leads to isocyanate (40-2). Treatment of this intermediate with benzyl alcohol then affords the corresponding carbamate (40-3). Catalytic hydrogenation removes the benzyloxy group, leading to the free primary amine. That product is then resolved by way of its camphorsulfonyl salt to afford (40-5). Reaction of this intermediate with desamino chloroadenosine (40-6) affords tecadenoson (40-7) [42]. 

On the basis of the above mentioned workup procedure a new simultaneous resolution method was developed using two moles of racemic tetrahydrofuroic acid (3b) instead of 12 for decomposition of complex 11 (Scheme 6, L= 8). In a methyl alcohol/water system the (S)-3b isomer built up a new crystalline coordination complex (13) while two moles of (R)-8 liberated and one mole of (R)-3b remained in the solution. [25]... 

Many furans and tetrahydrofurans were found to have exciting activity as ripeners for sugarcane. Among these, especially good results were obtained with tetrahydrofuroic acid hydrazide. 

In 1975, Kellyprepared and characterized a number of polyesters based on 2,5-disubstituted furans in various states of reduction. In this study, 2,5-disubstituted-furan, -dihydrofuran, and -tetrahydrofuran monomers were polymerized using solution, melt-transesterification, ring-opening, and interfacial techniques. These monomers included diacids, diols, diacid chlorides, diesters, dicarboxylic acid anhydrides, as well as monomers based on 5-hydroxymethyl-2-furoic and tetrahydrofuroic acids and esters, and bycyclic lactones containing the tetrahydrofuran ring. A thorough review of previous work done in the area of poljnner synthesis, based on 2,5-disubstituted furan derivatives is reported. It is reported that when... 

However, spectral data do not support the formation of polyether units. The NMR and IR spectra of the polyester prepared with triisobutyl aluminum were identical to those of the polyester prepared with Tyzor TPT or TBT. The NMR spectrum of the hydrolysis product was identical to that of cis-hydroxy acid except that the proton absorption for the hydroxyl methylene group was observed at 3.82 ppm, rather than at 3.93 ppm. It is likely that the solid isolated is trans-5-hydroxymethyl-2-tetrahydrofuroic acid. 

A high yield approach to the hexahydropyrrolo[3,2-e [l,4]diazepine-2,5-diones, 105 and their tetrahydrofuro analogues, 106, based on rearrangements of cyclopropylketimines and the cyclopropylketones, derived by acid hydrolysis, have been described. Thermolysis followed by DDQ oxidation of the unstable dihydro intermediates then gave compounds 105 (eg. R1 = Me, R2 = i-Bu) and 106 (eg. R = 4-Cl(C6H4)CH2) . 

Although the 3a,4,5,6a-tetrahydrofuro[3,2-fiQisoxazoles are unstable in the presence of Bronsted acids (e.g., Equation (58)), they are relatively stable to mild Lewis acids. As exemplified in Scheme 35, the combination of an organolithium and lithium bromide facilitates alkylative conversion of the isoxazoline nucleus (207) to the bicyclic isoxazolidines (208) and (209) <89CL1079>. A similar transformation was also reported for the tetrahydrofuro[3,4-fiQisoxazole (210) (Equation (59)). 

---