2- Chloro-oxirane

In reactions which have some analogy with the interaction of dichloro-carbene/trichloromethyl anions with ketones, 2-dichloromethyloxazolines yield chloro-oxiranes and a-chlorocarbonyl compounds (Scheme 7.18). The formation of the oxiranes is favoured with aldehydes and lower homologue ketones, whereas cyclic ketones and aryl ketones are converted preferentially into the a-chloro carbonyl derivatives [18]. 

The octahydrophenazine (149) has been obtained (82%) by the action of ammonia on the chloro-oxiran (148) followed by aerial oxidation other pyrazines can be similarly obtained. 

BASF worked out a procedure (second scheme on next page), which does not require any protecting group chemistry. Actinol is reacted at low temperature with dichloromethyilithium to form initially a chloro-oxirane, which undergoes upon warming a rearrangement to a bicydic aldehyde. The side-chain is... 

Six membered Rings.— The cycloadducts (277) are formed in good yield by reaction of sulphene with open-chain enaminones bearing a phenyl group at the 2-position.The conversion of 2-chloro-oxirans to 6-membered heterocycles has been described. The reaction with bidentate nucleophiles is most interesting, leading to mixed heterocycles such as (278). Tropone also reacts with 2-mercapto-ethanol to give a 95 5 mixture of the cyclohepta[l,2-6]-l,4-oxathiins (279), which could be separated by h.p.l.c. 

The Arbuzov-type reaction of trialkylphosphites with N-acyl aziridines gives the phosphonates (126), whereas a similar reaction with a-chloro-oxirans gives (127). In contrast, activated olefins (X = CN or C02Et) produce the pentaco-ordinate species (128) in the presence of R" OH. ... 

Similar to all commercial plastics, the traditional and more commonly used thermosetting resins are considered as petrochemicals, having been manufactured from petroleum. Some of the primary distillation products of crude oil, which can be classified either as olefins or aromatics, serve as precursors for the synthesis of thermosets. For example, epoxy resins are manufactured by the reaction of epichlorohydrin, a chloro-oxirane, and a derivative of propylene, with bisphenol A, which is a derivative of cumene. Another example would be the unsaturated polyesters (UPs), which are derivatives ultimately originating from ethylene (ethylene glycol) and benzene (maleic acid) [6]. Epoxies and polyesters constitute more than 95% of the thermoset composite market of the two, polyester-based systems predominate in volume by about 10-fold [6, 7]. Other thermoset resins used in reinforced form are phenolics, vinyl esters, and polyimides. Details of the properties and applications of these thermoset systems will be further discussed in the following section. 

The manufacture and uses of oxiranes are reviewed in (B-80MI50500, B-80MI50501). The industrially most important oxiranes are oxirane itself (ethylene oxide), which is made by catalyzed air-oxidation of ethylene (cf. Section 5.05.4.2.2(f)), and methyloxirane (propylene oxide), which is made by /3-elimination of hydrogen chloride from propene-derived 1-chloro-2-propanol (cf. Section 5.05.4.2.1) and by epoxidation of propene with 1-phenylethyl hydroperoxide cf. Section 5.05.4.2.2(f)) (79MI50501). 

Reaction of pyroc techol with epichlorohydrin in the presence of base affords the benzodioxan derivative, 136, (The reaction may well involve initial displacement of halogen by phenoxide followed by opening of the oxirane by the anion from the second phenolic group.) Treatment of the alcohol with thio-nyl chloride gives the corresponding chloro compound (137). Displacement of halogen by means of diethylamine affords piper-oxan (138), a compound with a-sympathetic blocking activity. 

Reaction of the carbanion of chloromethyl phenyl sulphoxide 409 with carbonyl compounds yields the corresponding 0-hydroxy adducts 410 in 68-79% yield. Each of these compounds appears to be a single isomer (equation 242). Treatment of adducts 410 with dilute potassium hydroxide in methanol at room temperature gives the epoxy sulphoxides 411 (equation 243). The ease of this intramolecular displacement of chloride ion contrasts with a great difficulty in displacing chloride ion from chloromethyl phenyl sulphoxide by external nucleophiles . When chloromethyl methyl sulphoxide 412 is reacted with unsymmetrical ketones in the presence of potassium tcrt-butoxide in tert-butanol oxiranes are directly formed as a mixture of diastereoisomers (equation 244). a-Sulphinyl epoxides 413 rearrange to a-sulphinyl aldehydes 414 or ketones, which can be transformed by elimination of sulphenic acid into a, 8-unsaturated aldehydes or ketones (equation 245). The lithium salts (410a) of a-chloro-/ -hydroxyalkyl... 

Before the discovery of the multifunctional kahilinols (cf. Sect. 4.2.2), ses-quiterpenoid isonitriles and related analogs were found distinctly void of other functions. Recent reports of isocyano analogs bearing hydroxy (46) [45], oxiran (10) [34], and chloro groups [86], for example, indicate the continued interest in the chemistry of marine isocyano compounds. 

O-Alkylation of 4-hydroxy-3-morpholino-l,2,5-thiadiazole 132 has been achieved with the chiral cyclic chloro-methyl sulfite 133 which subsequently suffers ring opening on treatment with simple alcohols <2001RCB436> or alkylamines <2002RJ0213> to afford the timolol analogues 134 with very little racemization (Scheme 20). This indicated an almost exclusive attack of the oxy anion on the exocyclic carbon atom and is a significant improvement on the previous oxirane method, which suffers from racemization. An alternative biocatalytic asymmetric synthesis of (A)- and (R)-timolol has also appeared <2004S1625>. 

Chloro(phenyl)carbene or carbenoid generated from benzal chloride reacts with potassium salts of benzylic, allylic, and other alkoxides to produce phenyl-substituted oxiranes 9 in high yields, as an approximately 1 1 mixture of cis... 

Upon slow warming of the matrix, the colour disappeared and a new species with A = 3.24 mT and gy = 2.0038 appeared, assigned to the formation of the chloro spin adduct [12] (32) after melting of the matrix at 240 K the characteristic solution epr spectrum of [12] was recorded. By y-radiolysis of the isomeric oxirane [13], which cannot sustain spin trapping, another way of direct matrix generation of PBN + was available and thus made possible further confirmation of these results (Zubarev and Brede, 1995). 

The p-bromo (or chloro) alcohol (50 ml) in PhH (330 ml) is refluxed with aqueous NaOH (29%, 17 ml) and TEBA-CI (3.3 g, 18 mmol) for 0.5-1 h. The cooled organic phase is separated, washed well with H20, dried (Na2S04), and evaporated to yield the oxirane, which can be purified by chromatography. 

Oxiranes undergo ring-opening with cerium(VI) ammonium nitrate and an excess of a quaternary ammonium halide to yield haloethanols [34], The reaction occurs with high regio- and stereo-selectivity, for example, / (+)-styrene oxide produces S(+)-2-chloro-2-phenylethanol in 85% yield with 96% ee. 

Synonyms AI3-03545 BRN 0079785 Caswell No. 424 CCRIS 277 l-Chloro-2,3-epoxypro-pane 3-Chloro-l,2-epoxypropane (Chloromethyl)ethylene oxide (Chloromethyl)oxirane 2-(Chloromethyl)oxirane 2-Chloropropylene oxide y-Chloropropylene oxide 3-Chloro-l,2-propyl-ene oxide ECH EINECS 203-439-8 EPA pesticide chemical code 097201 a-Epichlorohydrin (d -a-Epichlorohydrin Epichlorophydrin l,2-Epoxy-3-chloropropane 2,3-Epoxy propyl chloride Glycerol epichlorohydrin NCI-C07001 NSC 6747 RCRA waste number U041 UN 2023. 

Chloromethyl) oxhane, see Epichlorohydrin 2-(Chloromethyl)oxirane, see Epichlorohydrin 4-Chloro-3-methylphenol, see p-Chloro-ro-cresol p-Chloro-3-methylphenol, see p-Chloro-ro-cresol Chloromethyl phenyl ketone, see a-Chloroacetophenone p-Chloronaphthalene, see 2-Chloronaphthalene 4-Chloronitrobenzene, see p-Chloronitrobenzene l-Chloro-4-nitrobenzene, see p-Chloronitrobenzene 4-Chloro-l-nitrobenzene, seep-Chloronitrobenzene p-Chloro-1-nitrobenzene, see p-Chloronitrobenzene Chloronitroform, see Chloropicrin Chloronitropropane, see 1-Chloro-l-nitropropane Chlorophen, see Pentachlorophenol... 

Epichloro- hydrin Epichloro- hydrin Polychrloro- methyl oxirane CO Poly(cpi- chloro hydrin) Poly[oxy- (chloro- methyl) ethylene] CH 136 40-90 18 350 251... 

A novel method of opening of oxiranes involves the use of (chlo-romethylene)dimethyliminium chloride (39) [see Section II,2c p. 250], monochlorodeoxy or dichlorodideoxy derivatives are obtained, depending upon the reaction conditions employed.83 Thus, methyl 2,3-anhydro-4,6-0-benzylidene-a-D-allopyranoside (110) reacts with 39 in 1,1,2,2-tetrachloroethane at room temperature to give, upon hydrolysis of the primary adduct 111 with an aqueous solution of sodium hydrogen carbonate, methyl 4,6-0-benzylidene-2-chloro-2-deoxy-3-0-formyl-a-D-altropyranoside (112). If a solution of 39 and 110 in 1,1,2,2-tetrachloroethane is heated at reflux temperature, methyl 3,4-0-benzylidene-2,6-dichloro-2,6-dideoxy-o -D-altropyrano-side (113) is obtained in high yield the n.m.r. spectrum of 113, like that of 47 (see Section II, 2c p. 250), showed the presence of two diastereoisomers which differed in the configuration of the benzyl-idene-acetal carbon atom. 

R)-ALKYLOXIRANES OF HIGH ENANTIOMERIC PURITY FROM (S)-2-CHL0R0ALKAN0IC ACIDS YIA (S)-2-CHLORO-l-ALKANOLS (R)-METHYLOXIRANE (Oxirane, methyl- (R)-)... 

To 61 % HF/pyridine (30 mL) was added 2-(chloromcthyl)oxirane (14 g, 0.15 mol) over 90 min at 0 C. The product was isolated 5 min after the addition was completed, either by extraction with CC14 or by quenching the mixture with ice water, followed by extraction with CHC13. The organic layer was separated, dried (MgS04 or Na2S04) and the solvents distilled off and l-chloro-3-fluoropropan-2-ol isolated by distillation at reduced pressure yield 8.4 g (50%) bp 50"C/l Torr. 

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