Acid-induced transannular cyclization of 2-methyl- and 10-methyl-5-cyclodecenone
作者:Yongliang Chu、James B White、Brian A Duclos
DOI:10.1016/s0040-4039(01)00618-9
日期:2001.6
2-Methyl- and 10-methyl-5-cyclodecenone were made by anionic oxy-Cope rearrangement of the corresponding 1,2-divinylcyclohexanols, and their transannularcyclizations were induced using trifluoroacetic acid. In each case, a single diastereomer of a trans fused bicyclo[4.4.0]decan-1-ol with an equatorial methyl group was isolated. The methyl substituent at C2 or C10 of the 5-cyclodecenone did not alter
Pd(II)-Catalyzed cyclogeneration of carbocations: subsequent rearrangement and trapping under oxidative conditions
作者:Jeong Hwan Koh、Cheryl Mascarenhas、Michel R. Gagné
DOI:10.1016/j.tet.2004.06.023
日期:2004.8
A catalytic oxidative polycyclization reaction initiated by the carbocyclization of 1,5-dienes with Pd(II) is reported. Trapping of a putative carbocation with suitable functional groups (phenols, alkenes, alcohols, sulfonamide), or rearrangement protocols (Pinacol) yields poly-cyclic products in good yields and in excellent diastereoselectivities. Turnover of the intermediate Pd–C bond is via β-H
Palladium-Catalyzed Cyclization of 1,ω-Dienols: Multiple Ways to Intramolecularly Trap a Carbocation
作者:Vasily N. Korotchenko、Michel R. Gagné
DOI:10.1021/jo0705871
日期:2007.6.1
The tandem catalytic cyclization-rearrangement of 1,omega-dien-3-ols by palladium(II) produces different types of products, depending on the structure of starting material. The pinacol rearrangement, benzannulation, and oxy-Cope rearrangement are major pathways of transforming the putative sigma-alkylpalladium carbocation. Turnover of the cyclization is achieved by beta-hydride elimination and reoxidation of palladium with benzoquinone. The overall course of the reaction is very sensitive to small changes in the substrate structure.
A facile preparation of differentiated 1,2-divinylcycloalkanols