Cyclohex-3-en-l-ols

Cyclic allylic alcohols fairly easily cycloadd dichlorocarbene, particularly if generated under chloroform/base/phase-transfer catalyst conditions. Five- and six-membered-ring allylic alcohols form a mixture of cis- and tranx-isomers, while those of larger rings form only the trans-isomer. In contrast with the phase-transfer catalysis method, dichlorocarbene generated from bromodichloromethyl(phenyl)mercury did not add to cyclohex-3-en-l-ol, while cyclonon-3-en-l-ol yielded exo-10,10-dichlorobicyclo[7.1.0]decan-2-ol (28%), which could not be purified.155 Examples of dichlorocarbene adducts to cyclic allylic alcohols are presented in Table 19. 

Product studies on the oxidation of cyclohexene by a combination of PdClg and CUCI2 in acetic acid show that in addition to cyclohex-2-en-l-ol and cyclohex-3-en-l-ol acetates obtained in the absence of Cuii, the saturated disubstituted chloroacetate or diaeetate derivatives are also observed. The relative activities of tetra-, penta-, and hexa-chlororhodate(m) complexes as catalysts for the oxidation of ethylene to acetaldehyde in aqueous acid media have been described, and in the presence of iron(m) and other oxidants in the same media the complex ion [RhClsOHaO)] " is considered to promote the reaction. 

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