Dauben studies

In 1963, Dauben and Berezin published the first systematic study of this syn directing effect (Scheme 3.15) [37]. They found that the cyclopropanation of 2-cyclohexen-l-ol 32 proceed in 63% yield to give the syn isomer 33 as the sole product. They observed the same high syn diastereoselectivity in a variety of cyclic allylic alcohols and methyl ethers. On the basis of these results, they reasonably conclude that there must be some type of coordinative interaction between the zinc carbenoid and the substrate. 

Dauben et al. have shown from the study of simple model trienes that this conformation favors the formation of the ( 4 + 2) producttl35) (see Table 9.6) ... 

Dauben and coworkers produced a number of lovely examples of the reaction in the course of their studies of the photochemistry of large-ring (Cs-Cn) cyclic trienes, many of which were produced by photochemical electrocycloreversion of the isomeric annulated cyclohexadiene derivatives (cf Reference 172 and references cited therein). Two examples... 

Several examples of the photochemistry of larger-ring (C9-C12) cyclic trienes have already been cited (vide supra), and a great many more have been studied, particularly by Dauben and coworkers. These have been reviewed thoroughly elsewhere in general,... 

The photochemistry of all these compounds is of interest with respect to the well-known photochemistry of cyclohexadiene (1.3) derivatives, for instance, the photochemical reactions of 2.4.6-triaryl-cyclohexadien(2.4)-on-ol(2) series of Perst and Dimroth or in a more comprehensive context the photochemical transformation of ergosterol, luniisterol, isopyrocalciferol and pyrocalciferol which were first studied by Windaus and Dimroth and fully investigated by Veluz, Havinga and Dauben... 

Photolysis of oe-chloro-o-methylacetophenones yields 1-indanones. The mechanism has been studied by laser flash photolysis (Netto-Ferreira, J. C. Scaiano, J. C., J. Am. Chem. Soc., 1991, 113, 5800). Develop a Dauben-Salem-Turro state correlation diagram for the photochemical step and, on the basis of your diagram, discuss the efficiency of the reaction on the singlet and triplet manifold. Do the experimental results agree with your analysis ... 

The key underlying assumption of all the NMR studies of the homotropenylium systems is that there is an induced ring current when the ions are in a magnetic field and that this effects the two C(8) protons in a different manner. Dauben, Wilson and Laity measured the diamagnetic susceptibility of 11 and showed that it has a susceptibility exaltation which is similar in magnitude to that of the tropylium ion88. 

Dauben and Wolf (73) have also studied the chemical reduction of a series of acyclic cyclopropyl ketones 1252-254) with lithium in liquid ammonia. 

The nontethered styrene cycloadditions initially reported by Dauben [16] have been further studied by Caldwell [14b]. The 1-phenylcyclohexene... 

Lifson S, Hagler AT, Dauben P (1979) Consistent force field studies of intermolecular forces in hydrogen bonded crystals. I. Carboxylic acids, amides and the C-O—H hydrogen bonds. J Am Chem Soc 101 5111-5121... 

After Dauben s observation that trityl perchlorate produced 9-phenylfluorene upon day-li t exposure van Tamelen and Cole systematically studied the photolysis of the trityl ion in various acidic media with visible light from a medium-pressure mercury... 

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