2-Phenyl-l,2-butanediol

The optical purity was determined after conversion to (-)-(5)-3-mcthyl-2-phenyl-l, 2-butanediol. 

Therapeutic Function Tranquilizer Chemical Name 2-Phenyl-l,2-butanediol-l-carbamate Common Name Oxyfenamate Structural Formula ... 

Hydroxyphenamate. 2-Phenyl-l,2-butanediol 1-carbamate carbamic acid ft -ethyl -0-hydroxy phenethy] ester d-ethyl-p-hydroxyphenethy] carbamic acid ester 0-ethyl-0-hydroxy phenethyl carbemate 2-hydroxy-2-phenyl-butyl carbamate Al 0361 Listica. C.,H.sNOv mol wt 209.24. C 63.14%, H 7.23%, N 6.69%, O 22 94%. Prepd from d-ethyl -d-hydroxyphenethyl alcohol and ethyl chloro-formate followed by reaction with ammonia Sifferd, Brait-berg. U,S. pat. 3,066,164 (1962 to Armour-Pharm.). Pharmacology and toxicology Bastian, Clements, Di-V. Nerv. Sys. 22, 9 (1961). 

Problem 14.59 Outline the steps and give the product of pinacol rearrangement of (a) 3-phenyl-l,2-propanediol, (b) 2,3-diphenyl-2,3-butanediol. ... 

Optically active lactones are valuable building blocks in organic synthesis (4) and in the preparation of optically active biodegradable polymers (7,5). Several chemical methods for producing these compounds and their corresponding polymers have been explored (6) but unfortunately all of these methods are either experimentally cumbersome or afford the lactones with only modest enantioselectivities. Examples of chemically prepared optically active polyesters include poly(a-phenyl-P-propiolactone) (7), poly(a-ethy(-a-phenyl-P -propiolactone) (S, 9), poly(a-methyl-a-ethyl-P-propiolactone) (70) and poly(lactic acid) (77, 72). Use of enantioselective polymerization catalysts to carry out stereoelective polymerizations of racemic lactones has produced mixed results. For example, stereoelective polymerization of [/ ,S]- P-methyl-P-propiolactone with a catalyst from Zn ( 2115)2 and [7 ]-(-)-3,3-dimethyl-l,2-butanediol showed only a small enantiomeric enrichment in the final polymer (75). Stereoselective copolymerizations of racemic (LL/DD monomers) and meso (LD monomer) lactides using chiral catalyst that gives heterotactic and syndiotactic PLA, respectively have also been studied (77). 

Ligustrum also contains a unique volatile oil consisting primarily of esters and alcohols, with lesser amounts of thioketones, hydrocarbons, and traces of amines and aldehydes, but no terpene hydrocarbons. Major components of the volatile oil include ethyl acetate (18.95%), thioketone (8.56%), a-butyl-benze-nemethanol (5.6%), 4-acetyloxy-2-butanone (5.46%), 1-phenyl-1,2-butanediol (4.12%), 1,2-diphenyl-l,2-ethanediol (3.92%), hydra-zine-methyl-oxalate (3.52%), a,a,4-tri-methyl-3-cyclohexene-methanol (3.24%), 1-methyl-l-propyl-hydrazine (2.60%), and (Z)-1 -(1 -ethoxy-ethoxy)-3-hexene (1.89%). ... 

We have systematically examined the facility with which DTPP promotes the cyclodehydration of simple diols to cyclic ethers 1,3-propanediol (1) - oxetane (2) (2-5%) 1,4-butanediol (3) te-trahydrofuran (4) (85%) 1,5-pentanediol (5) - tetrahydropyran (6) (72%) 1,6-hexanediol (7) - oxepane (8) (55-68%). Increased alkyl substitution at the carbinol carbon s gnificantly diminishes the facility for cyclic ether formation. For example, a mixture of meso- and d, 1 —2, 6-heptanediol gave only 6-10% of the cis- and trans-2,6-dimethyltetrahydropyrans when treated with DTPP. While diol 1 resists cyclodehydration with DTPP to oxetane, some 2,2-di-substituted 1,3-propanediols are readily converted to the appropriate oxetanes [e.g., 2-ethyl-2-phenyl-l,3-propanediol -> 3-ethyl-3-phenyloxetane (78%)]. 

The volatilities of 13 polonium compounds that are soluble in organic solvents was investigated. All of the compounds were found to volatilize below 200 °C at atmospheric pressure. Polonium was found to form soluble organic compounds with the following chelating agents 2, 3-butanediol 4, 4, 4-trifluoro-l-(2-thiene) 8-quinoline diethyldithiocarbamate thiocarbanilide 1, 5-diphenylcarbohydrazide l-phenyl-3-thiosemicarbazide thiosemicarbazide and thiourea. 

A similar example is seen in the [Pd2(dba)3]-catalyzed hydroboration of 2-methyl-l-buten-3-ynes [274]. While PPhj and PPh2(CgF5) favor the 1,4-addition product allenylborane 100 all diphosphines yield the 1,2-addition product ( )-dienylborane 102 exclusively (Table 1-13). This remarkable difference in selectivity is explained based on an 1,3-enyne monophosphine complex 103 and an alkynyl diphosphine complex 104 as intermediates. Dppf exhibits the best product yield among the phosphines tested. Similar observation was noted in the asymmetric hydroboration (Scheme 1-44) [275]. The action of catecholborane on 1-phenyl-1,3-butadiene also proceeds regioselectively to give, after oxidation, anti-l-phenyl-l,3-butanediol... 

DBU proved to be an effective and selective catalyst for the tert-butyldimethylsilylation of primary and secondary alcohols at ambient temperature in different solvents in the presence of DBU (85BCJ3669). It is assumed that DBU forms a complex 602 with tcrt-butyldimethylchlorosilane, which subsequently reacts with alcohols. The fcrt-butyldimethylsilylation of the tertiary hydroxy group did not occur after even a prolonged reaction time. When 2-ethyl-l,3-hexanediol, 1,3-butanediol, and 1-phenyl-1,2-ethanediol were reacted, the corresponding primary silyl ether was obtained almost exclusively. 

Electrogenerated nickel(I) salen has been used as a catalyst for the reductive intramolecular cyclizations of 6-bromo- and 6-iodo-l-phenyl-1-hexyne [338], the reduction of several Q ,ft)-dihaloalkanes [339], the reductive coupling of 2-bromo- and 2-iodoethanol to prepare 1,4-butanediol [340], the conversion of cyclohexanecarbonyl chloride to a tetramer [341], and the reduction of benzal chloride [342]. 

V, racemic rro/i5-methyl-l,2-cyclohexanediol, inversion W, racemic and meso-HOCH2CHOHCHOHCHTOH X, racemic 2,3-butanediol Y, me50-2,3-butanediol. 16. m-Methylanisole. 17. K, anisyl alcohol. 18. (a) / r/-Butyl ethyl ether (b) w-propyl ether (c) isopropyl ether. 19. L, / methylphenetole M, benzyl ethyl ether N, 3-phenyl-1-propanol... 

Fragmentation processes of photoinitiators form a number of volatile products, which may contribute to indoor air pollution. Benzaldehyde and alkyl-substituted benzalde-hydes are usual components, because Norrish-I is the most important reaction for cleavage. Awell known example is l-phenyl-2-hydroxy-2-methyl-propane-l-one (PHMP). a-Cleavage generates two radicals in the first step. The benzoyl radical may recombine to form benzil, reduction of PHMP leads to l-phenyl-2-methy 1-1,2-propane and acetone, and recombination of the 2-hydroxypropyl radical gives 2,3-dimethyl-2,3-butanediol... 

Butanediol mixed with some TiCl4, 2/3 mole of benzaldehyde added gradually, and the product isolated after 24 hrs. 2-phenyl-4-methyl-l,3-dioxane. Y 92%. F. e., also ketals, s. P. Mastagli, P. Lambert, and D. Baladie, C. r. 255, 2978 (1962). 

Also obtained by heating 2-phenyl-4-benzylidene-7-hydroxy-[4 T -l-benzopy-ran (SM) with refluxing aqueous sodium hydroxide for 1 h. SM was obtained by condensation of l,4-diphenyl-l,3-butanediol with resorcinol in acetic acid [5269]. 

Treatment of A-1 -phcnyl-2-butcnc 5 with I2 and silver benzoate (1 2) followed by saponification gives an equal mixture of [2.S ,3A -l-phenyl-2,3-butanediol and 12 A ,3. S -1 -phenyl-2,3-butancdiol. Treatment of 5 with I2 and silver acetate in the presence of water followed by saponification gives an equal mixture of [2A ,3A -1-phenyl-2,3-butancdiol and [2.S ,3.S -1-phenyl-2,3-butanediol. Determine the stereochemistry for these two processes. Can you account for the difference mechanistically ... 

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