Pyrrolo isoquinoline skeleton

To build the central ABC core present in 1, two main synthetic strategies have been used Diels-Alder reactions and asymmetric synthesis. This tricyclic subunit was chosen as the first synthetic target because it contains all five stereogenic carbons. A central pyrrolo-isoquinoline skeleton (ABC) was initially synthesized by the high-pressure Diels-Alder reaction of 3-alkyl-5,6-dihydro-2-pyridones with Danishefsky s diene, followed by deprotection and spontaneous pyrrolidine ring closure (see Scheme 16) [77]. 

The two-step one-pot total synthesis of Ro 22-1319, an antipsychotic agent featuring a rigid pyrrolo[2,3-g]isoquinoline skeleton, was accomplished by D.L. Coffen and co-workers. The cyclic 1,3-diketone precursor was prepared from arecoline and dimethyl malonate, and in the same reaction vessel an amino ketone hydrochloride was added. The pH of the reaction mixture was adjusted to 4 in order to initiate the formation of the pyrrole. 

Synthetic Studies on Manzamine A II A novel Diels-Alder Approach to the Pyrrolo[2,3-j]isoquinoline skeleton. Torisawa, Y. Nakagawa, M. Arai, H. Lai,... 

Y. Torisawa, M. Nakagawa, H. Aral, Z. Lai, T. Hino, T. Nakata, T. Oishi, Synthetic studies on manzamine A11 a novel Diels-Alder approach to the pyrrolo[2,3- ]isoquinoline skeleton. Tetrahedron Lett. 31 (1990) 3195-3198. 

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See also in sourсe #XX -- [ ]

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