McCRAE : DI-SEC.-OCTYL TARTRATE. 1221 CXX1V.-Di-See. - Octyl Tartrate and Di-see. - Octyl Bibenxo ylt urtra f e. By JOHN MCCRAE. IT has already been explained (Trans., 1901, 79, 1103) that by the action of an acid chIoride on a tartaric ester containing alkyl groups high in the series it was anticipated that it would be easy to obtain- a monoacyl derivative. When one ethyl group of diethyl tartrate is replaced by an octyl group (Zoc. cit.), no indication could be found that the latter exerts any ‘‘ surrounding ” influence to prevent the easy introduction of two acyl groups. The second ethyl group has also been replaced by the octyl radicle, but even then there is no evidence of a, hindering influence exerted by the alkyl groups on the reactivity of the hydroxyl radicles of the tartaric molecule.In the preparation of the dioctyl tartrate, the same sec.-octyl alcohol was used as formerly. Dioctyl Tartmte. Ethyl octyl tartrate was prepared by the method already described and 35 grams of it were dissolved in 150 grams of octyl alcohol ; the solution was saturated in the cold with dry hydrogen chloride, and after standing at the ordinary temperature for three days the hydrogen chloride was extracted under reduced pressure and the residue distilled.1222 McCRAE : DI-SEC.-OCTYL TARTRATE AND The fraction distilling above 215' under 15 mm. pressure had a rotation of 4.15' in a 50 mm. tube a t 20'. This fraction was rectified and the oil which passed over at 215-225O under 19 mm. pressure showed a rotation of 4.05' in the same tube at 18.5'. The whole of the distillate which had passed over above 200' was washed with water, and after drying was dissolved in octyl alcohol ; the solution was then saturated with hydrogen chloride and treated as before.On dis- tilling the oil left after the extraction of the hydrogen chloride, a fraction was obtained which boiled at 225O under 20 mm. pressure and had a rotation of 3*60° i n the 50 mm. tube a t 18'. This rotation was not altered by redistillation of the ester, and the same rotation was obtained with different fractions of the same dictillation. Dioctyl tartrate is a viscous, slightly yellow oil with a rancid odour. The following density determinations were made : d 32'/4'= 1 *0077. d 45O/4'= 0.9967. The density a t 18O would be 1*0195; consequently [ a y - 3'6 =7*06', and [M]r =26*30'.- 0.5 x 1.0195 Dioctyl Dibennxoyltartmte. Preliminary experiments showed that by the action of benzoyl chloride on dioctyl tartrate a laevorotatory product was formed, and this, in analogy with the results which have been obtained for diethyl tartrate (Frankland and Wharton, Trans., 1896, 69, 1586), dibutyl tartrate (Freundler, Ann. Chim. Phys., 1894, [ vii 3, 3, 479), and ethyl octyl tartrate (Trans., 1901, 79, 1106), indicated that two acyl groups may easily be introduced into the molecule. It was evident, too, that the introduction of a single acyl group would be a matter of some diaculty, and consequently the original view was not realised. The dibeneoyl derivative was prepared by heating 40 grams of benzoyl chloride to 140° and slowly dropping in 9 grams of dioctyl tartrate with repeated shaking.The mixture was heated at the same temperature for two days until there was no further evolution of hydro- gen chloride. It was then poured into water and thoroughly shaken during two days with sodium carbonate solution. The oil was dissolved in ether, and the ethereal solution shaken with aqueous sodium car- bonate solution until the odour of acid chloride completely disappeared. The ethereal solution was washed, dried over ignited potassium car- bonate, then filtered, after which the ether was distilled off. A dark, oily residue was left which was dissolved in alcohol and shaken with charcoal. After filtering off the charcoal, the solution was quicklyDI-SEC.-OCTYL DIBENZOYLTARTRATE.1223 heated and water was added until there was just a permanent turbidity. On cooling, a slightly yellow oil was precipitated which, after drying, gave a rotation of - 22'50' in a 50 mm. tube. The oil was further purified by dissolving in alcohol and precipitating with water ; it was then dissolved in ether, dried over potassium carbonate, and the ether distilled off. The oil, which was yellowish and possessed a slightly rancid odour, was dried over sulphuric acid under reduced pressure, and gave a rotation of - 23'59' in a 50 mm. tube at 25'. Further treatment by the same method did not alter the rotation : 0*1320 gave 0,3390 GO, and 0.0856 H20. The following density determinations were made : C = 70.04 ; H = 7.20. C,,H,,O, requires C = 70.1 1 ; H = 7.90 per cent.d 2lo/4O= 1.0953. d 3Ot5O/4O = lq0860. CE 45'/4'== 1.0725. The density at 25O would therefore be 1,0913 ; eossequentIy [ a ] r = - 23'98 = -43.94', and [MITE -355.70. 0.5 x 1*0913 As the polarimeter used was not fitted with a heating arrangement, it was not possible to determine the influence of temperature on the rotation to find whether, in the case of the benzoyl compound, this passes through a maximum, as Frankland and Wharton (Trans,, 1896, 69, 1586) found to be the case with diethyl dibenzoyltartrate. Conclusions. The ester described above extends the series of tartaric esters, and for comparison the following table may be given : Dimethyl tartrate * ............ Dietbyl tartrate * ............... Di-n-propyl t,artrate * ......... Di-isopropyl tartrate * ......Di-rt-butyl tartrate t ......... Di-isobutyl tarfrate * ......... Di-sec.-oct yl tartrate ............ Ethyl sec.-octyl tartrate $ ...... [ u ] F = 1.83' [u]": = 7.66 [uK =12.44 [ u ] F =14*89 [ U]T = 10.3 [ ~]1,0~' = 19.87 [u]F = 7.06 [u]r = 7-78 [N]1,8"= 3.26' [MK = 15.18 [M]y= 27-37 [M]2,0" = 32 76 [My = 13-80 [M]bma= 26.62 [M]F = 26.30 [MJT = 22.55 The similarity of the specific rotations of diethyl and dioctyl tar, trates is striking, and may possibly be due to a rise of rotatory power t o a maximum, with subsequent rapid fall as the series of esters is ascended (see Frankland, Trans., 1899, 75, 547). The relationship * Pictet, Jahrmbcr., 1882, 856. t Freundler, A m . Chim. Phys., 1894, [vii], 3, 447. 3; McCrae, Trans., 1901, 79, 1106.1224 HARDEN AND YOUNG: GLYCOGEN FROM YEAST.between the rotations of diethyl and dioctyl tartrates is very similar to that between the rotations of ethyl glycerate and octyl glycerate, or t o that between the rotations of ethyl ncetylglycerate and octyl acetyl- glycerate quoted by Frankland (Zoc. cit., 354 and 355). Taking the view previously expressed, that substitution effected sufficiently far removed from the asymmetric carbon atom scarcely modifies the rotatory power, we may here find a confirmation of Guye’s proposition ,(Trans., 1901, 78, 476), inasmuch as substitution of a methglene hydrogen atom in the ethyl group of ethyl octyl tartrate by n-hexyl causes only a small increase in the molecular rotation, and the increase is only small even if we consider the replacement of a methyl- ene hydrogen atom of each of the ethyl groups of diethyl tartrate by cn-hexy 1. The comparatively high negative rotation of dioctyl dibenzoyl- tartrate shows that the introduction of two aromatic acyl groups into the tartaric molecule changes the dextrorotation into a lavorotation (Frankland and Wharton, Freundler, McUrae, Eoc. cit.), and it would therefore appew that this is quite general and is independent of the nature of the alkyl groups present. TEE YORKSHIEB COLLEGE, LEEDS.