Target molecular structure

Scheme 1). Introduction of a jt bond into the molecular structure of 1 furnishes homoallylic amine 2 and satisfies the structural prerequisite for an aza-Prins transform.4 Thus, disconnection of the bond between C-2 and C-3 affords intermediate 3 as a viable precursor. In the forward sense, a cation ji-type cyclization, or aza-Prins reaction, could achieve the formation of the C2-C3 bond and complete the assembly of the complex pentacyclic skeleton of the target molecule (1). Reduction of the residual n bond in 2, hydro-genolysis of the benzyl ether, and adjustment of the oxidation state at the side-chain terminus would then complete the synthesis of 1. 

Within a given animal species, in addition, the selection of target organs, at least under certain dosing schedules, may also be an explicit function of molecular structure. 

Computer aided molecular design (CAMD) problems are defined as, Given a set of building blocks and a specified set of target properties Determine the molecule or molecular structure that matches these properties. 

In this respect, CAMD technique [Gani et al. (1991)]is the reverse problem of property prediction, where, given the identity of the molecule (or the molecular structure) or a mixture, a set of target properties is calculated. In this chapter,... 

Step 3 Generate and Test - use any CAMD technique (and software, for example, ProCAMD) to automatically generate and test candidates. The selected CAMD technique should be able to generate molecular structures and evaluate their properties with respect to the specified target properties. 

Already, the virion-associated reverse transcriptase has been highlighted as a target. The RT gene has been cloned, and the gene product can be produced in large quantities. Several molecules of very diverse molecular structure, such as zidovudine, suramin, and rifabutin, have been shown to cause inhibition of the... 

In the first place, the structure of the target molecule is submitted to a rational analysis in order to perceive the most significant structural features, and it may be useful to use different types of molecular models at this point. It should be remembered that a molecular structure has "thousand faces" and finding the most convenient perspective may greatly simplifly the synthetic problem. The synthesis of opium alkaloids, for instance, is much simplified if one realises that they are, in fact, derivatives of benzyltetrahydroisoquinoline (18) (see Scheme 3.8). This was indeed the inspired intuition of Sir Robert Robinson which led to the structural elucidation of morphine (19) and to a first sketch of the biogenetic pathway [22], and later on to the biomimetic synthesis of thebaine 20 [23] [24]. 

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