Acetic anhydride crystal structure

One of the best known compounds is the so-called manganic acetate. This dark red substance is obtained as a hydrate by action of KMn04 on a hot solution of Mn11 acetate in glacial acetic acid the anhydrous compound can be obtained by crystallization from acetic acid containing acetic anhydride. The structure has only recently been determined and it now appears that the acetate is a basic acetate similar to those of Fe111 and Crlu (page 837). Thus it has the stoichiometry... 

The one-step reaction of H2prCl6] with MeC02Li under 02 in a mixed solvent of acetic acid and acetic anhydride yields the Ir11 binuclear complex [Ir2(/u-02CMe)2Cl2(C0)2].483 Crystal-structure determinations of [Ir2(/x-02CMe)2Cl2(C0)2L2], (295), where L = MeCN, DMSO, and py, are reported. The one-electron oxidation product for (295), L = py, is EPR active at 77 K the odd electron occupies the 6Ir Ir orbital. 

Reaction of B20(0Ac)4 with sodium acetate results in the formation of Na[B20(0Ac)5] with O and OAc bridges, whereas acetatoborates, M[B(OAc)4] (M = K, Rb, Cs, Tl), are obtained when the reaction is conducted in the presence of acetic anhydride. These borates are easily hydrolyzed in the case of [B(OAc)4]- the rate determining step seems to be dissociation of the complex. Binuclear "borates M2[B20(0Ac)6] and M2[B202(0Ac)4], were detected, inter alia, during thermal decomposition of tetraacetatoborates.132 The crystal structure of K[B(OAc)4] has been determined.133... 

Recently, clusters (18) with one capping oxygen atom and one capping ethylidyne moiety have also been prepared.237 The +1 cluster is prepared by refluxing W(CO)6 with a mixture of acetic add and its anhydride in MeCN. A one electron oxidation of the +1 ion leads to the +2 ion, whose crystal structure analysis reveals a W—W distance of 2.81 A. This distance is significantly longer than the one observed for (15), in agreement with the fact that the +2 ion is a five electron system and therefore the W—W bond order is less than unity. 

The mixed-metal dimer [CrMo(02CMe)4] has been prepared in 30% yield by addition of [Mo(CO)6] in acetic acid, acetic anhydride and CH2C12, to a refluxing solution of [Cr2(02CMe)4(H20)2] in acetic acid and acetic anhydride.13 The yellow product is volatile and gives the expected parent ion peak in the mass spectrum. It has a Raman active v(Cr—Mo) mode at 394 cm-1 consistent with quadruple bonding. The crystal structure gives a metal-metal... 

During the isolation of denudatine, Gotz and Wiesner (135) also isolated a new alkaloid, designated as delnudine (149), from the seeds of D. denudation. Preliminary spectral data revealed the presence of two hydroxyls, a cyclohexanone, and an exocyclic double bond in proximity with the ketone. The presence of the tertiary carbinolamine moiety was demonstrated by the formation of a basic diacetate (150) and a neutral 0,JV-diacetate (151) on acetylation with acetic anhydride in pyridine. They demonstrated that one of the ketones in compound 151 was derived from the carbinolamine moiety. Finally, the structure of delnudine was established as 149 by a single-crystal... 

Since these products are, therefore, readily available as starting materials we have studied their further use. The diazido compounds 38 are not very stable. They loose readily dinitrogen (usually on crystallization from alcohol) and give the tetrazolyl derivatives 39. Treatment of 39 with acetic anhydride leads in the usual way (cf. the conversion of 3 via 9-11 to 12) to the oxadiazolyl derivative 40. The carbonyl group in this structure can be reduced with sodium borohydride to the methylene group. Careful hydrolysis of this compound (41) with acid, yields the hydrazide 42, while alkaline hydrolysis of both affords the acid 43 [84JHC1881],... 

The starting material for the acylase process is a racemic mixture of N-acetyl-amino acids 20 which are chemically synthesized by acetylation of D, L-amino acids with acetyl chloride or acetic anhydride in alkaU via the Schotten-Baumann reaction. The kinetic resolution of N-acetyl-D, L-amino acids is achieved by a specific L-acylase from Aspergillus oryzae, which only hydrolyzes the L-enantiomer and produces a mixture of the corresponding L-amino acid, acetate, and N-acetyl-D-amino acid. After separation of the L-amino acid by a crystallization step, the remaining N-acetyl-D-amino acid is recycled by thermal racemization under drastic conditions (Scheme 13.18) [47]. In a similar process racemic amino acid amides are resolved with an L-spedfic amidase and the remaining enantiomer is racemized separately. Although the final yields of the L-form are beyond 50% of the starting material in these multistep processes, the effidency of the whole transformation is much lower than a DKR process with in situ racemization. On the other hand, the structural requirements for the free carboxylate do not allow the identification of derivatives racemizable in situ therefore, the racemization requires... 

M. Lounasmaa,9 of the Technical University of Helsinki. Otaniemi. Finland, refluxed for several hours a solution of 2,6-dimethoxy-l, 4-benzoquinone in acetic anhydride in the presence of sodium acetate, added water, and isolated by extraction with chloroform and crystallization from acetic acid a colorless product melting at 149-150° which, on the basis of analysis (C14H160 ). mass spectrography. and IR and N MR spectroscopy, was assigned the structure (6). 

HjCuOj, mol wt 122.58. C 19.59%, H 2.47%, Cu 51.83%, O 26.10%, CHjCOOCu, Obtained as a sublimate by heating cupric acetate in vacuo to temps above 220" Angel, Har-oourt, J. Chem. Soc. 81, 1385 (1902) prepn from cuprous oxide and acetic acid -acetic anhydride Shimizu, Weller, J-Am. Chem. Soc. 74, 4469 (1952). Crystal structure T. 

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