Natural products and derivatives

Fig. 3. Natural products and derivatives accessed through solid supported reagent technology...

An obvious way to target chiral compounds is to start with a compound in which the chiral center is already present. Here natural products and derivatives offer a rich pool of generally inexpensive starting materials. Examples include L-hydroxy and amino adds. Sometimes, just one out of many chiral centers is predestined to remain, as in the synthesis of vitamin C from D-glucose, or in the preparation of (S)-3-hydroxy-y-butyrolactone from ladose. 

Newman DJ, Cragg GM, Holbeck S, Sausville EA, Natural products and derivatives as leads to cell cycle pathway targets in cancer chemotherapy, Curr Cancer Drug Targets 2 279-308, 2002. 

Houghton PJ, Howes MJR, Natural products and derivatives affecting neurotransmission relevant to Alzheimer s and Parkinson s disease, Neurosignals 14 6-22, 2005. 

Natural products and derivatives (such as sugars or /Mactam antibiotics) are treated as normal cyclic compounds. The natural product substructure is treated as a substituent or as a chiral auxiliary in the cyclic compound section. 

In this revised section, some recent examples have been selected emphasizing applications of enzymes to generation of natural products and derivatives and precursors combined with some of the latest technical developments. 

A new marine fungal, tentatively identified as Fusarium heterosporum, produced a series of compounds with spirotricyclic framework, mangicols A-G 1-7 The stereochemistry determination of 1 was based on spectral data from both the natural product and derivatives synthesized. The mangicols 1-7 showed only weak to modest... 

W. Fenical P. R. Jensen X. C. Cheng, Halimide, a Cytotoxic Marine Natural Product, and Derivatives Thereof. U.S. Patent 6,069,146, 1998. 

Methoxy- and ethoxy-substituted quinolines were metalated and condensed with a variety of electrophiles to yield, after other steps, a variety of natural products and derivatives (58). Among the condensing agents were ethylene oxide and allyl bromide, and the heterocyclic... 

Fenical W, Jensen PR, Cheng XC (2000) Avrainvillamide, a cytotoxic marine natural product, and derivatives thereof. U.S. Patent 6,066,635... 

Before venturing into describing various strategies developed for the synthesis of propargyl alcohols in optically pure form, it would be interesting to look at various bioactive natural products and derivatives synthesized starting from this multifunctional... 

In a continuation of their work on the synthesis of azaphilone natural products and derivatives [135], Porco and co-workers disclosed in 2012 the synthesis of azaphilone-based chemical libraries [136]. Phenolic ortAo-alkynylbenzaldehydes 260 were cycloisomerized via a gold(lll) catalysis in the presence of TFA to afford... 

Introduction. Indolizine was discovered in 1890 and reportedly first synthesized in 1912. The conpound is a IOtt aromatic system although it has limited reported utility as the parent compound itself, its atomic framework is found in a number of alkaloid natural products and derivatives possessing pharmaceutical or agrochemical function. Methods to prepare and elaborate the indolizine suhunit have heen reviewed. ... 

Alkaloids incorporating six-membered nitrogen heterocycles are abundantly present in nature and occur in a multitude of alkaloid natural product families. Many of these alkaloids exhibit a wide range of diverse biological activities. As a result, extensive research has been devoted to the synthesis of many of the natural products and derivatives. This has led to an enormous variety of synthetic methodology that has been efficiently applied to synthesize many of these alkaloids. Among these methods, metathesis-based processes have played an increasingly important role as is illustrated in the sequel. 

When an olefin happens to be attached to the ring that has been formed after an initial ene-yne RCM, a new bicychc moiety can be formed by a second RCM. Such metathetical transformation is highly useful for the constraction of polycyclic ring systems and it has been apphed in the synthesis of natural products and derivatives to a great extent Herein, we report a selection of the most significant examples (Scheme 11.4). 

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