1,2-Epoxypropane preparation

Figure 8. NMR spectrum in CDCI3 of poly(1,2-epoxypropane) prepared by the polymerization with chloroaluminum tetraphenyl-porphyrin (1c). m, r, I, S and H represent meso, racemo (diad) and isotactic, syndiotactic, and heterotactic (triad) sequences, respectively.

About 2 X 10 Ib/year of 1 2 epoxypropane is produced in the United States as an intermediate in the preparation of various polymeric materials including polyurethane plastics and foams and polyester resins A large fraction of the 1 2 epoxypropane is made from propene by way of its chlorohydrm... 

Propylene oxide [75-56-9] (methyloxirane, 1,2-epoxypropane) is a significant organic chemical used primarily as a reaction intermediate for production of polyether polyols, propylene glycol, alkanolamines (qv), glycol ethers, and many other useful products (see Glycols). Propylene oxide was first prepared in 1861 by Oser and first polymerized by Levene and Walti in 1927 (1). Propylene oxide is manufactured by two basic processes the traditional chlorohydrin process (see Chlorohydrins) and the hydroperoxide process, where either / fZ-butanol (see Butyl alcohols) or styrene (qv) is a co-product. Research continues in an effort to develop a direct oxidation process to be used commercially. 

Diphenoxy-2-propanol (3) was prepared from phenol and epichlorohydrin (l-chloro-2,3-epoxypropane), as previously described,8 and recrystallized three times from 2-propanol to yield white crystals, m.p. 82-82.5°C. The nmr spectrum in CDC1- (Varian EM-390 spectrometer) exhibited resonances (in ppm (6) relative to tetramethylsilane) at 3.0 (1H, doublet,... 

The utility of the creation of a y-lactone enolate through 1,4-addition of a carbanion and its interception by an electrophile has also been demonstrated in other classes of natural products, e.g., in the enantioselective synthesis of 10-oxa-l 1-methyl PGE2 analogues22. This synthesis starts with 1,4-addition of the sulfone-stabilized anion from 27 to ( + )-(S )-4-methyl-2-buteno-lide which has been prepared in three steps from (—)-(S)-l,2-epoxypropane. The intermediate enolate 28 is reacted with the acetylenic iodide to give the trisubstituted diastereomeric mixture of lactones 29, which is eventually converted into the pure compound 30, both reactions occurring with high diastereoselectivity. 

The epoxide required in the first step, 1,2-epoxypropane, is prepared as follows from isopropyl alcohol ... 

The easy ring-opening behavior of hexafluoro-1,2-epoxypropane in the presence of a nucleophile has also been useful as a synthetic tool for the preparation of thiazolo[3,2-a]benzimidazol-3(2//)-ones. Sodium salt of benzimidazolyl-2-thionc (247) reacts with hexafluoro-1,2-epoxypropane in an aprotic solvent, such as dioxane or CH3CN, to give 2-fluoro-2-(triflu-oromethyl)-thiazolo[3,2-a]benzimidazol-3(2//)-one (260) (81S981). The sodium salt of thione 247, acting as a nucleophile, readily attacks the... 

A large number of substituted 1,3-epoxides as well as the parent oxetane (oxacyclobutane, trimethylene oxide, 1,3-epoxypropane) have been prepared and polymerized. Likewise a wide variety of substances have been used to initiate their polymerizations. Much of this work has been extensively reviewed previously [1, 3, 7] and the interested reader is referred to these earlier reviews. Here we confine ourselves to reporting representative major kinetic studies. In this section the organization is by monomer. 

A number of chlorinated poly(ethers) have practical uses. A common compound from this group is polyepichlorohydrin, [-CH(CH2CI)CH20-]n. Polyepichlorohydrin has practical applications as an elastomer and is used in copolymers with propylene oxide, ethylene oxide, allyl glycidyl ether (1-allyloxy-2,3-epoxypropane), etc. Another example is poly oxy[2,2 -bis(chloromethyl)-1,3-propandiyl] or poly[oxy-1,3-(2,2 -dichloromethyl)propylene], CAS 25323-58-4, which can be used as inert lining material for chemical plant equipment, as adhesive, coating material, etc. This macromolecule can be prepared starting with pentaerythritol in the sequence of reactions shown below ... 

Dialkyl 2,3-epoxypropylphosphonates are readily prepared by heating trialkyl phosphites and 1-bromo- or l-iodo-2,3-epoxypropane at 130-140°C. Between these two precursors, the 1-bromo-... 

Reagent-grade 2,3-epoxy-l-propyl methacrylate and vinylpyridines were distilled at reduced pressure, and the middle fractions were collected for use. 1-Ethenyl-4-( 2,3-epoxy-l-propoxy)benzene was prepared from 4-ethenylphenol and l-chloro-2,3-epoxypropane by a two-step process (] ). 2,2 -Azoisobutyronitr ile was recrys-... 

---