139607-63-9Relevant academic research and scientific papers
Use of Dilithiomethane Equivalent in a Novel One-Flask Cyclopentannulation Reaction: A Highly Efficient Total Synthesis of (+/-)-Hirsutene
Ramig, Keith,Kuzemo, Michael A.,McNamara, Kevin,Cohen, Theodore
, p. 1968 - 1969 (1992)
A brief synthesis of (+/-)-hirsutene demonstrates the novel use of tris(phenylthio)methane as a dilithiomethane equivalent capable of consecutive conjugate additions to different enones to form a dienolate which can be oxidized to a cyclopentane.
A novel one-flask cyclopentannulation involving a dilithiomethane equivalent as a β-connector of two enones. A highly efficient total synthesis of (±)-hirsutene
Cohen,McNamara,Kuzemko,Ramig,Landi Jr.,Dong
, p. 7931 - 7942 (1993)
Five- and six-membered rings can be constructed in one flask from two different enones and tris(phenylthio)methyllithium. The latter behaves as a dilithiomethane equivalent when its central carbon atom adds in conjugate fashion to one enone, becomes nucleophilic again when one of its phenylthio groups is exchanged for lithium in the presence of sec-butyllithium, and then undergoes conjugate addition to a second enone to provide a dienolate dianion. The latter can be oxidized to a 1,4-diketone incorporating a cyclopentane ring or induced to undergo an aldol reaction to produce a six-membered ring. In some of the cases, an interesting stereochemical equilibration occurs during the oxidation leading to one of two possible diastereomers and the overall process results in a highly efficient, stereospecific synthesis of (±)-hirsutene 13.
