Reporting intermediate

B) Synthesis of C ring Scheme 13.6.3 shows the synthesis of aldehyde 19, which contains the required C ring of taxol, from the previously reported intermediate 14. ... 

Unfortunately the authors argue that they were performing mechanochemical reactions with mechanical energy input for the salt formation or complexation to occur, rather than just creating the required contacts between reacting crystals. Furthermore, they did not exclude moisture, reported intermediate liquid phases in various cases, and did not separate out any real solid-state reactions that might have been achieved. It is therefore not possible to discuss the results in more detail here. 

Sullivan B, Hudlicky T (2008) Chemoenzymatic formal synthesis of (—)-balanol. Provision of optical data for an often-reported intermediate. Tetrahedron Lett 49 5211-5213... 

Several studies reporting intermediate oral exposure of children to white phosphorus were located. In most cases the white phosphorus was administered as a treatment for rickets, but in some cases white phosphorus was administered to healthy children to prevent the development of rickets. In studies reporting the effects of white phosphorus on bones in children, the doses of white phosphorus administered (0.026-0.158 mg/kg/day) were several orders of magnitude lower than those reported following intentional or accidental white phosphorus poisoning. 

Application of this synthetic sequence to the earlier reported intermediate 321 should lead to the total synthesis of denudatine. 

Fig (19) Octalin ketal (163) is converted to kete dithioacetal (164) by the cleavage of ketal function and condensation with carbon disulfide and methyl iodide. Subjection of (164) to the action of dimethylsulfonium niethylide and acid hydrolysis leads to the formation of unsaturated lactone (165).lts furan silyl ether derivative is caused to undergo Diets-Atder reaction with methyl acrylate to obtain salicyctic ester (166) which is converted by standard organic reactions toabietane ether (167). It is converted to aiiylic alcohol (168) by epoxidation and elimination. Alcohol (169) obtained from (168) yields orthoamide which undergoes transformation to amide (170). Its conversion to the previously reported intermediate has been achieved by epoxidation, elimination and hydrolysis. 

Isopropyl anisole (171) was converted to bromide (172) by metalation, formylation and bromination. Alkylation with cyclopropyl ketoester produced (173) whose transformation to alcohol (174) was achieved by saponification, decarboxylation and reduction.. Its conversion to homoallylic bromide (175) was accomplished by the method of Julia et al. [56]. Alkylation of ethyl acetoacetate with bromide (175) furnished p-ketoester (176). It was subjected to cyclization with stannic chloride in dichloromethane. The resulting tricyclic alcohol provided the olefinic ester (177) by treatment with mesylchloride and triethylamine. Epoxidation followed by elimination led to the previously reported intermediate (146) whose conversion to triptolide (149) has already been described. 

Each of the three oxides of lead is important technologically PbO in ceramics, Pb304 in paints, and Pb02 in the widely used lead-storage-battery. Other reported intermediate oxides of lead (such as Pb203 and PbsOe) have not been convincingly characterized. 

Solid-phase synthesis of the substituted thiophenes 197 has been reported. Intermediates 196, derived from resin-bound ester 195, react with a-bromo ketones, and treatment of the resulting products with NaOMe affords the thiophenes 197 (Scheme 38) <2003T4851>. 

The network includes 4 MS, 10 NMS and 3 ACC. Activities carried out in 17 countries need a timely and firm coordination. Therefore, the management of SAFEFOODNET is assigned to a specific work package (WP1). WP1 addresses the co-ordination of administrative and scientific areas of the project. It will assure a well-timed delivery of internal and official documents. WP1 has the task to create and maintain the administrative and technical archive of accounts, contractual record, and progress reports, intermediate and final deliverables. Moreover, the management will include organisation of project meetings communication with European Commission, circulation of documents to partners. 

The preparation of ii/-H-dehydroaldosterone (261) by classical steps from the 3,20-bisethyleneketal of d/-3,20-dioxo-ll, 21-dihydroxypregn-5-en-18-oic acid (18 1 l)S)-lactone (262), a previously reported intermediate in the total synthesis... 

Precision - integration, particularly at low sample amounts, may be difficult and an assessment of the precision of the experiment is needed. As alluded to above there are three levels of precision testing repeatability, intermediate precision and reproducibility. Repeatability expresses the precision under the same operating conditions over a short interval of time. This is frequently the only precision information provided in literature reports. Intermediate precision expresses within-laboratory variations across different days, different analysts, different equipment, etc. and it is a key indicator of how an assay will perform under real conditions. Reproducibility expresses the precision between laboratories and typically only becomes important if a method is transferred between laboratories - for example, from an R D site to a manufacturing facility. 

AF-RF2 Pseudocubic perovskite-related CsEuFs with a = 4.77 A is the only reported intermediate compound (Shafer, 1965). 

A Michael reaction-Claisen condensation involving the previously reported intermediate (4) derived from galactose (see... 

A synthesis of ureas on solid-phase by the formation of carbamoyl chlorides from secondary amines and phosgene or triphosgene has been reported. Intermediate carbamoyl chlorides can be reacted with primary or secondary amines to give urea products in high yield and with high chemical purity [120]. 

The derivative (20) can be obtained from its C-2 epimer by formation of the anion and kinetic protonation deprotection then yields 2-deoxy-a-NeuiVAc. Zbiral s group have reported the synthesis of the 7-epi-, and 8-epi-, and 7,8-bis-epi- analogues of 2-deoxy-a-NeulVAc, together with the 2,7- and 2,8-dideoxycompounds, by manipulation of previously known intermediates this paper also describes an improved synthesis of 2-deoxy-a-Neu/VAc methyl ester.21 The hydroxymethyl derivative (21) has been prepared from the previously reported intermediate (22) (Vol. 22, p.l60) as outlined in Scheme 6 similar chemistry involving the C-4 epimer of (22) and the C-4 ketone was used for the synthesis of the 2-epimer and 2,4-bis-epimer of (21).22... 

Fraser-Reid s group have described further examples of the use of serial radical cyclization to prepare di- and triquinane natural products. The previously-reported intermediate (4) (Vol. 23, p. 264) has been ring-opened by a Vasella-Bernet reaction, and hence converted to the triquinane (5) with the silphinene skeleton (Scheme 2). Similar initial steps were involved in the conversion of (6) into silphiperfolene (7), and to transform (8) (Vol. 23, p. 265) into (-)-a-pipitzol (9) (mannose carbons numbered). ... 

Reaction of a previously-reported intermediate (Vol. 22, p. 216) with hydrazine has led to a synthesis of the pyridazine (136), and the same group have reported that treatment of (137) with o-phenylenediamine, followed by DDQ, gives the homo-C-nucleoside (138). 0... 

Previously reported intermediates (Vol.27, p.253-4) have been converted into other nucleoside analogues with two-carbon chains at C-2, such as the selectively-protected triol 87, prepared by reduction of the lactone 86. 2 -C-Methyl ribonucleosides have been made by Vorbriiggen-type coupling of the appropriate base to a sugar unit (see Chapter 14). 

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