Wolff reviews

E. W. Wolff, Review, Signals of atmospheric pollution in polar snow and ice, Antarct. Sci., 2 (1990), 189-205. 

This reaction is discussed extensively in an eadier review (41). In the Huang-Minlon modification of the Wolff-Kishner reaction, a high boiling solvent such as diethylene glycol is used to achieve the required high temperatures (180—210°C) without the use of pressure equipment (42). The base is generally alkaU hydroxide or an alkoxide (43). 

Both the Wolff-Kishner and Clemmensen reductions of a, -unsaturated ketones give olefins. There has been considerable confusion concerning the exact product composition in the case of A -3-ketones. Wolff-Kishner reduction gives A" -, 5a-A - and 5 -A -olefins, and, depending on the substrate reaction conditions and work-up, any one or more of these may be isolated. (See ref. 287 for a recent review of the Wolff-Kishner reduction.)... 

The photolytic decomposition of a-diazoketones, accompanied by rearrangement to ketene (photolytic Wolff rearrangement), has been used successfully in the preparation of A-nor- and C-norsteroids. The method is reviewed in chapter 15 by R. M. Scribner. ... 

The photolysis of o-quinone diazides was carefully investigated by Stis in 1944, many years before the development of photoresists. Scheme 10-102 shows the photolysis sequence for the diazoquinone 10.75 formed in the diazotization of 2-amino-1-naphthol. The product of the photolytic step is a ketocarbene (10.76), which undergoes a Wolff rearrangement to a ketene (10.77). In the presence of water in-dene-3-carboxylic acid (10.78) is formed this compound is highly soluble in water and can be removed in the development step. The mechanism given in Scheme 10-102 was not postulated as such by Stis, because in 1944 ketocarbenes were unknown (for a mechanistic discussion of such Wolff rearrangements see review by Zollinger, 1995, Sec. 8.6, and Andraos et al., 1994). 

Wolff, R.D., Callari, A. and Roberts, B. (1984) A Marxian alternative to the traditional transformation problem Review of Radical Political Economics, 16 115-35. 

Zeller, K.-P. Blocher, A. Haiss, P. Oxirene participation in the Photochemical Wolff Rearrangement Mlnl-Revlewx in Organic Chemistry 2004,1, 291-308. (Review). 

Wolffe, A.P. and Guschin, D. (2000) Review chromatin structural features and targets that regulate transcription. Journal of Structural Biology, 129, 102-122. 

Other synthetic routes to the carbapenem ring system include photolytic Wolff rearrangement (73JCS(P 1)2024), aldol condensation (78JA313), addition-cyclization (80JOC1135) and /3-lactam formation (78JOC4438,79TL4359). An excellent review of carbapenem synthesis has recently appeared (82H(17)463). 

Figure 7, adapted from a forward-looking review by Wolff and Maggio... 

The same assay procedure should be used for specimens from an individual. Some background in the use of urinary estriol as an index of placental function may be found in a number of reports on the use of this valuable clinical chemistry tool in obstetrics. More recently, Wolff et al. (5) reviewed the various pathologies and abnormalities of pregnancy versus values of estriol levels in urine. 

A short review of the first 100 years of ketene chemistry covers haloketenes, Wolff (g) rearrangements, stereoselective nucleophilic attack, dimerization, cycloadditions, ketene-Claisen and -Cope reactions, bisketenes, and free radical processes.12 ... 

A O-Diacetyldihydropseudosolasodine (12a) gave the epimeric pyrrolidines (13) on treatment with bromine. When N-bromosuccinimide was used as oxidant, the ketone (12b) and the pyrrolidine (14) were also formed.17 The WolfF-Kishner reductions of solasodenone (9b) and of the epimeric 4,5 -dihydro-analogues have been reported.18 Solasodine gave the expected 5a,6-epoxide on treatment with perbenzoic acid.19 The preparation of an intermediate in the synthesis of the solanidine alkaloids has been reviewed.20... 

The antiaromatic oxirenes 11 are extremely elusive but their potential involvement in photochemical Wolff rearrangements by equilibration with the -oxocarbenes 12 has generated both theoretical and experimental interest and the subject has been reviewed <2004MR0291>. Experimental evidence for participation of oxirenes <2004MR0291> is supported by DFT calculations that suggest that oxirene corresponds to an energy minimum <2003JMT(629)263, CHEC-III(1.03.7)215>. 

While the consistency between the reported experimental E° values for the Br/Br" couple is encouraging, it should be noted that all values rely upon the reported equilibrium constant for reaction (18). As noted in Fornier de Violet s review (127), the magnitude of this formation constant is contentious, with reported results ranging from 3.3 x 103 to 2.2 x 105 M l. The most recent value is 1.1 x 10s M-1, and it is the value accepted, albeit reluctantly, in this review. An estimate of E° can be made that is relatively insensitive to this equilibrium constant by using some recently available data. Klaning and Wolff reported that for... 

Due to its high efficiency and regioselectivity, the Wolff rearrangement was extensively studied and reviewed, with copper or silver being the most efficient metals for this transformation (121). Similar reactivity can be achieved via ultraviolet (UV) light, sonication, or microwave irradiation (122). A free carbene-based pathway was proposed as a general mechanism. Basic additives are usually required when silver is used as the catalyst Silver nanoclusters are known to form under such conditions, which may serve as the real catalyst (Fig. 24) (123,124). 

Background information on the chemistry of oxirenes is presented in Chapter 1.03, and this area has been reviewed by Zeller <2002SOS(9)19>. The potential antiaromatic character of oxirenes, the strain of the unsaturated three-membered ring, and the possible involvement in important reactions (e.g., oxidation of alkynes, Wolff rearrangement)... 

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