L-Threitol

Fig. 1. Stmctures of the tetritols (a) erythritol, (b) D-threitol, and (c) L-threitol and the pentitols (d) ribitol, (e) D-arabinitol, (f) L-arabinitol, and (g) xyhtol.

Amino-sugars and Related Compounds. Part VII. 2-Amino-2-deoxy-1,3,4,5-tetra-O-methyl-D-glucitol, 2-Amino-2-deoxy-L-threitol and Certain Derivatives Thereof, A. B. Foster, D. Horton,... 

Scheme 4-21 shows the preparation of L-threitol and L-erythritol.38 Epoxy alcohols (2J ,3iS)-61 and (2S,3/ )-61. generated by asymmetric epoxidation, are exposed to sodium benzenethiolate and sodium hydroxide in a protonic solvent to undergo base-catalyzed rearrangement, yielding the threo-diol 62 and erythro-diol 63, which can then be converted to the corresponding tetraacetate of l-threitol 67 and L-erythritol 69 through subsequent transformations. 

Among the 1,4-di-O-substituted-L-threitol derivatives (Figure 14a) the one that has found most use in chiral crown ether synthesis is the 1,4-dibenzyl ether. Not only has it provided (88, 106, 107) a ready entry into the chiral tetrasub-stituted 18-crown-6 derivatives ll-31 to ll-34, but it has also proved to be a usehil chiral precursor for the preparation of chiral disubstituted 9-crown-3 (107), 12-crown-4 (108), 15-crown-5 (108), and 18-crown-6 (109) derivatives l-57, l-58, l-59, and l-60, respectively. In the preparation of l-S8 the base-promoted cyclization with triethylene glycol ditosylate is best carried out (108) with a... 

A base-promoted reaction between L-threitol and tetraethylene glycol di-tosylate afforded (165) the chiral bis(15-ctown-5) derivative l-146 as well as the trans-fused bicyclic system l-147 containing 15-crown-5 and 17-crown-5 rings. These constitutional isomers, which were separated chromatographically, were characterized by preparing l-147 unequivocally by a stepwise route from 2,3-O-isopropylidene-L-threitol. 

B. 2,3-Di-0 iaopropylidene-L-threitol (Note 13). In a dry, 2-L, threenecked, round-bottomed flask equipped with a 500-mL pressure-equalized addition funnel, reflux condenser, thermometer, and a large magnetic stirring bar. Is suspended lithium aluminum hydride (36 g, 0.95 mol) (Note 14) In diethyl ether (600 mL) (Note 15) under argon. The mixture Is stirred and heated to reflux for 30 min. Heating is discontinued while a solution of... 

D. 1,4-Di-O-benzyl-L-threitol. The crude ketal is dissolved in methanol (300 mL), 0.5 N hydrochloric acid (30 idL) is added, and the resulting mixture Is heated to reflux. Acetone and methanol are slowly distilled off (Note 29). Additional methanol (50 mL) and 0.5 N hydrochloric acid (20 mL) are added and the mixture Is kept at room temperature until ketal hydrolysis Is complete. The mixture Is diluted with saturated sodium bicarbonate solution (500 mL) and extracted with ether (3 x 500 mL). The ether extracts are combined, dried over anhydrous magnesium sulfate, and filtered. Removal of volatile material under reduced pressure gives crude l,4-di-0-benzy1-L-threitol as a pale yellow solid. This solid is recrystallized twice from chloroform/hexanes, to provide 59-65 g (195-215 mmol, 57-63% yield) of pure diol, up 54-55 C (Notes 30 and 31). Concentration of the mother liquors from the recrystallizations gives a yellow solid which is chromatographed on 70-230 mesh silica gel 60 (500 g) (Note 32), and eluted with 50% ethyl... 

Homochiral molecules readily available from inexpensive sources are useful synthetic building blocks and chiral auxiliaries. 1,4-01-0-benzyl-L-threitol has been used in construction of homochiral crown ethers that are useful as enzyme model systems. Topologically controlled diastereoselective delivery of the Simmons-Smith reagent for 2-cycloalken-l-one 1,4-d1-0-benzyl-L-threitol ketals was recently reported. ... 

The preparation of l,4-d1-0-benzyl-L-threitol described here from L-tartarlc acid via 2,3-0-isopropyl1dene-L-thre1tol is adapted from work by Carmack, Felt, and Inouye. This general route has been employed by the... 

Di-0-1sopropylidene-L-threitol 1,3-Di oxolane-4,5-dimethano1, 2,2-dimethyl-, (4S-trans)- (9) (50622-09-8)... 

Eugene A. Mash, Keith A. Nelson, Shawne Van Deusen, and Susan B. Hemperly 92 1.4- DI-O-ALKYL THREITOLS FROM TARTARIC ACID 1.4- DI-O-BENZYL-L-THREITOL... 

Galbis and Munoz-Guerra et al. used the secondary G-protected L-threitol, L-arabinitol and xylitol (5-12) as monomers for the preparation of a series of linear [/M, ]-type polyurethanes 97 and 98 by polycondensation in solution with... 

Erythritol and L-threitol have also been dehydrated by means of 50% sulfuric acid at 120° to the corresponding 1,4-anhydrides.6 On heating erythritol in the presence of a small proportion of a xylene-sulfonic acid at 130-150° under vacuum, an 89% yield of 1,4-anhydro-DL-erythritol was obtained.7... 

Preparation of 1,4-Di-0-A1 kyl Threitols from Tartaric Acid 1,4-Di-O-Benzyl-L-Threitol... 

The selective removal of one of two acetal groups that are symmetrically disposed within a diacetal may be achieved. l,3 2,4-Di-0-ben-zylidene derivatives of erythritol and L-threitol have been converted41 into their 1,3-acetals, and selective methanolysis of 2,3,2, 3 -tetra-0-benzoyl-4,6 4, 6 -di-0-benzylidene-a,a-trehalose gave42 the mono-benzylidene derivative in 47% yield, thereby offering a route to un-symmetrically substituted a,a-trehalose derivatives. 

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