Conessine, dihydro

Dihydro-5,6-dihydroxyconessine has been prepared by the action of aqueous nitrous acid on conessine (7a).7 Treatment of conessine with BrCN yields the 7V-cyano-iV-desmethyl derivative (7b).8 The latter has been converted (by standard methods) into derivatives (7c), (7d), and (7e).9... 

The first successful introduction of a C(i8>-substituent was achieved independently by Corey and by Jeger, and their co-workers, in 1958. They applied the Hofmann-Loeffier Freytag reaction, an efficient method for preparing pyrrolidines by cyclisation of iV-haloamines, to the synthesis of dihydro-conessine 3) [2,3]. The process comprises irradiation of an Ar-chloro 20a-amine (i), in acid solution, when the chlorine atom is exchanged with a hydrogen atom at the unactivated C(i8) position. Later work on simple model compounds [4]... 

The partial synthesis of 5a-conanine was published by Jeger and Arigoni s group simultaneously with the partial synthesis of dihydro-conessine by Corey and Her tier. 

Conversion of formamides into isonitrUes. In the course of a synthesis of dihydro-conessine from 3/3-acetoxy-A -bisnorcholenic ticid, Corey and Hertler treated the formamide (1) with tosyl chloride in pyridine in the expectation of merely tosylating the 3 8-hydroxyl group. The product, however, was not (3) but the tosylate isonitrile... 

The alkaloids conkurchine, conessine, conessidine, holarrhine, and kurchine have been isolated from Wrightia tomentosa Irehdiamine F (la) has been isolated from roots of Vahadenia laurentii in the first investigation of this species the crystal and molecular structures of the hydrochloride of this base were investigated by single-crystal AT-ray diffraction methods/ A study has been reported on the nature of the binding of irehdiamine A (lb), and of the 5,6-dihydro-derivative of the latter base, to double-helical DNA/... 

A general class of reactions that has the potential to greatly increase AE is C—H activation chemistry [71], C—H activation is a broad term and generally refers to direct conversion of a C—H bond to a C—C or C—heteroatom bond. This is not a new concept with Corey s synthesis of dihydro-conessine (85) in 1958 representing an early example [72] (Scheme 13.13). A Hofmann-Loffler-Ereytag reaction was utilized to convert a C—H bond to a C—Cl bond, with the installed chloride being displaced by the proximal amine after exposure to base. 

The novel preparation of i+,5-dihydro-l8-hydroxyprogesterone from conessine has been reported in detail and involves the reaction of p-nitroperbenzoic acid with a 20-imine. ... 

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