Wo-Butyl alcohol

In a 2-1. three-necked flask fitted with a mechanical stirrer, a thermometer, and a dropping funnel, is placed 518 g. (643 cc., 7 moles) of dry wo-butyl alcohol (b.p. io6-io8°/76o mm.). This is cooled to —10° by immersing the flask in an ice-salt bat and 695 g. (244 cc., 2.56 moles) of phosphorus tribromide (Note if is slowly added with stirring at such a rate as to keep the temperature below 0° (about four hours). The cooling bath is removed, and stirring is continued until the mixture reaches room temperature it is then allowed to stand overnight. The stirrer, funnel, and thermometer are removed, and the flask is fitted with a 30-cm. fractionating column and a condenser. The crude i50-butyl bromide is distilled from the reaction mixture under diminished pressure e.g. at about 50° under 200 mm, (Note 2). 

Figure 5.1 (c) On (i) polar and (ii) non-polar capillary WCOT columns illustrating like attracts like polar/non-polar retention properties and two column analysis to confirm components present. Toluene is used as the reference marker. 1, Methyl alcohol 2, ethyl alcohol 3, isopropyl alcohol 4, n-propyl alcohol 5, wo-butyl alcohol 6, iec-butyl alcohol 7, rert-butyl alcohol 8, n-butyl alcohol 9, toluene (reference marker). Polar column Carbowax 20M (25m X 0.32, 0.25 pm film). Non-polar column HP-1, dimethylsiloxane (25m x 0.32, 0.25 pm film). Both columns carrier gas He 1ml min injection 0.5 pi split 20 1 detector FID column temperature programmed 50-200°C at 5°C min. ... 

The above is a general procedure for preparing trialkyl orthophosphates. Similar yields are obtained for trimethyl phosphate, b.p. 62°/5 mm. triethyl phosphate, b.p. 75-5°/5 mm. tri-n-propyl phosphate, b.p. 107-5°/5 mm. tri-Mo-propyl phosphate, b.p. 83-5°/5 mm. tri-wo-butyl phosphate, b.p. 117°/5-5 mm. and tri- -amyl phosphate, b.p. 167-5°/5 mm. The alkyl phosphates are excellent alkylating agents for primary aromatic amines (see Section IV,41) they can also be ua for alkylating phenols (compare Sections IV,104-105). Trimethyl phosphate also finds application as a methylating agent for aliphatie alcohols (compare Section 111,58). 

Diazomethane (rs, 3 Ciazomethane and its homologs are prq>ared by the action of sodium fju-propoxide in wo-propyl alcohol upon the products of nitrosation from /9-alkylamino-iso-butyl methyl ketones (obtained by adding the amine to mesityl oxide). Adamson and Kenner, J. Chem. Soc. 1935, 286. 

F) Preparation and Testing of Candidate Structures. Suitable candidate structures were then examined for relative efficacy in the mobilization of lead from lead-loaded mice. On the basis of previous studies in which we examined the relative ability of many compounds to remove cadmium from its aged deposits in the liver and the kidneys, six vicinal dithiols were selected, which were all monoesters of meso-2,3-dimercaptosuccinic acid. The compounds selected were the mono esters of meso- 2,3-dimercaptosuccinic acid with the following alcohols n-propyl, wo-propyl, n-butyl, wo-butyl, n-amyl, and iso-dmy (Figure 3). The results of experiments comparing these compounds showed that the n-butyl, iso-butyl, n-amyl, and isoamyl monoesters of m j<>-2,3-dimercaptosuccinic acid were the most effective compounds and that all were capable of reducing both kidney and brain lead levels in lead-intoxicated mice (45). The data collected on lead-intoxicated mice treated with the most effective of such compounds are compared with the results obtained with DMSA in Table I. 

An alternative approach to the synthesis of acitretin has been reported from enone 25 (Scheme 9),(42,43) Reduction of 25 followed by addition of acetylene afforded alcohol 29 in 67% yield. Treatment of 29 with 2-methoxy-l-propene in the presence of p-TsOH, followed by reaction with NaOH afforded diene 30. Treatment of 30 with wo-butyl chloroacetate yielded triene 32 via epoxide intermediate 31. Treatment of 32 with PBra and A, iV-dimethylacetamide followed by ester saponification completed a synthesis of acitretin in 6 steps and 25% overall yield. 

Enantioselective epoxidation of allylic alcohols using t-butyl peroxide, titanium tetra-wo-propoxide, and optically pure diethyl tartrate. 

C—H insertion reaction occurs in a stereoselective manner. Various attempts based on chiral lithium amide bases gave only moderate enantioselectivities. More efficiently, the reaction is carried out by means of s-butyl- or wo-propy 1-lithium in the presence of (—)-sparteine under these conditions, the bicyclic alcohol 92 was obtained in 74% yield and 83% ee. This concept has been extended to various meio-epoxides, an example of which is shown in equation 52. ... 

The extract of the pink/red coloured spot from the TLC plate was examined under the standard GC-EIMS conditions and by probe El MS. The fraction proved lo be a very complex mixture of components. However, no compounds were observed which could bo responsible for the colour. At least seven components were identified by mass spectrometry, including butyl carbitol, a phenol (component LI and (wo alcohols (components M and N ... 

One of the most important asymmetric syntheses is the Sharpless epoxidation. In this reaction, an allylic alcohol is transformed, by reaction with rerf.-butyl hydroperoxide (TBHP) in the presence of titanium tetra-wo-propoxide (Ti(/-PrO)4) and diethyl tartrate (DET), to the corresponding epoxy alcohol, with high enantiomeric purity. By the application of either (+)- or (-)-DET, the reaction product with the desired stereochemistry can be obtained [1,2] (Scheme 1). "O" (-)-DET... 

Typical derivatives of the first type are the various esters (Me, Et, Pr, iso-Pi, Bu, wo-Bu, cc-Bu, Am, tio-Am, etc.) of A -acyl (acetyl, TEA, PFP, HFB, etc.) amino acids. The butyl esters of iV-TFA amino acids owing to the frequency of their use even have a special abbreviation TAB derivatives. The two-stage process includes the esterification of amino acids by an excess of the corresponding alcohol in the presence of HCl and, after the evaporation of volatile compounds, the treatment of the non-volatile hydrochlorides of alkyl esters by acylating reagents (Fig. 1). 

---