2-Methylene-1,3-propanediol

Kaneko et al. reported the preparation of the key intermediate (-F)-12 of (—)-HA via the asymmetric Pd-catalyzed bicycloannulation of the p-keto ester 2 with 2-methylene-1,3-propanediol diacetate 11 (Scheme 4-8). The chiral ferrocenyl-phosphine ligand 13 gave 64% ee enantioselectivity. 

C4H802 2-methylene-1,3-propanediol 3513-81-3 408.11 35 130 2 3623 C4H9CIO 1 -chloro-2-methyl-2-propanol 558-42-9 401.65 34.521 1,2... 

Methylene-l,4-alkanediols. The PdCl2-(PhCN)2 - SnCl couple transforms an allylic alcohol into an allyl anion equivalent. 2-Methylene-1,3-propanediol can be used to prepare 2-methylene-1,4-alkanediols on reaction with carbonyl compounds. 

Related Reagents. Methallyl chloride Methallyl Bromide Methallyl Alcohol 3-Chloro-2-chloromethyl-l-propene 2-Methylene-1,3-propanediol. 

Nearly insoi in w, easily sol in ale, eth, et ac, benz gelatinizes NC. Can be prepd by the nitration of ], 3-propanediol with mixed nitric-sulfuric acid, as described by Naoum (Ref 4) and Blechta (Ref 3). The nitration requires a lower temp than that used for nitrating glycerin, because the central methylene group is readily oxidized at a higher temp. A temp between 0-10° is recommended since decompn is possible even at 15°, while at 20° yel fumes are evolved. Separating the product from the spent acid occurs with ease at 10°. From lOOp of... 

PTT is made by the melt polycondensation of PDO with either terephthalic acid or dimethyl terephthalate. The chemical structure is shown in Figure 11.1. It is also called 3GT in the polyester industry, with G and T standing for glycol and terephthalate, respectively. The number preceding G stands for the number of methylene units in the glycol moiety. In the literature, polypropylene terephthalate) (PPT) is also frequently encountered however, this nomenclature does not distinguish whether the glycol moiety is made from a branched 1,2-propanediol or a linear 1,3-propanediol. Another abbreviation sometimes used in the literature is PTMT, which could be confused with poly(tetramethylene terephthalate),... 

Propyleneimine is reported to react with a solution of absolute nitric acid in methylene chloride to yield 1,2-propanediol dinitrate, presumably via the intermediate primary... 

Axenrod and co-workers reported a synthesis of TNAZ (18) starting from 3-amino-l,2-propanediol (28). Treatment of (28) with two equivalents of p-toluenesulfonyl chloride in the presence of pyridine yields the ditosylate (29), which on further protection as a TBS derivative, followed by treatment with lithium hydride in THF, induces ring closure to the azetidine (31) in excellent yield. Removal of the TBS protecting group from (31) with acetic acid at elevated temperature is followed by oxidation of the alcohol (32) to the ketone (33). Treatment of the ketone (33) with hydroxylamine hydrochloride in aqueous sodium acetate yields the oxime (34). The synthesis of TNAZ (18) is completed on treatment of the oxime (34) with pure nitric acid in methylene chloride, a reaction leading to oxidation-nitration of the oxime group to em-dinitro functionality and nitrolysis of the A-tosyl bond. This synthesis provides TNAZ in yields of 17-21 % over the seven steps. 

The purified intermediate melted at 210°C. 70.9 g (0.10 mol) of the intermediate was dissolved in 150 ml dimethylacetamide, and 15 g (0.08 mol) tributylamine was added. The mixture was heated to 50°C, and 56.6 g (0.62 mol) 1,3-dihydroxyisopropylamine (2-amino-l,3-propanediol) dissolved in 80 ml dimethylacetamide was added drop by drop. The reaction went to completion within a few hours, and the reaction mixture was evaporated to dryness in a vacuum. The oily residue was added to 350 ml methylene chloride with vigorous agitation, and the resulting precipitate was filtered off and purified by repeated suspension of warm methylene chloride. 

Fig. 1. Polyhydric alcohols. Systematic names are (1) 2,2-bis(hydroxymethyl)-l,3-propanediol (2) 2,2-[oxybis(methylene)]-bis[2-hydroxymethyl]-l,3-propanediol (3) 2,2-bis [3-hydroxy-2,2-bis(hydroxymethyl)propoxy]methyl -1,3-propanediol (4) 2-hydroxy-methyl-2-methyl-1-2-methyl-1,3-propanediol (5) 2-ethyl-2-hydroxymethyl-l,3-propanediol and (6)...

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