The crystal structure of pentaerythritol tetracetate.

Although the technique for investigating organic crystals by X-rays is now fairly well developed, there are still many important types of compound of which no representative has yet been examined. In particular no Fourier analysis of an ester has ever been published and no reliable information is available as to the lengths of C—O and C=O bonds in such substances. The investigation of pentaerythritol tetracetate recorded here was made partly to supply this deficiency and partly to develop the study of pentaerythritol (Llewellyn, Cox and Goodwin 1937). A further incentive lay in the doubt which existed at one time regarding the distribution of the valencies of the central carbon atom in the tetracetate; this is discussed in § III. The results of the investigation are presented at once, the methods by which they were deduced being described in the last section.