Cyclodecene synthesis

The potential utility of the stereocontrol available through exo [6 + 4] cycloaddition in the tropone series can be seen in Garst s stereoselective cyclodecene synthesis. This methodology is predicate on the efficient translation of the double bond geometry from stereochemically homogeneous ( )- and (Z)-1-acetoxybutadiene via cycloadducts (30) and (35) into ( )-cyclodecene (36) and (Z)-cyclod ne (3, respectively. Reduction of cycloadducts (30) and (35) to the corresponding fiiUy saturated ketoacetates, followed by conversion to the mesylates and hydride reduction, led to the desired 10-membered ring products (36) and (37) in 78% and 40% yields, respectively. 

Cyclodecene synthesis by RCM is rare, and typically requires high dilution conditions. Rychnovsky and co-workers have prepared cyclodecene 127 by exposing a 1 mmol solution of 128 to 20 mol% G2 (Scheme... 

Based on the successful series of transformations summarized in Scheme 1, Schreiber and Santini developed an efficient and elegant synthesis of periplanone B (1),8 the potent sex pheromone of the American cockroach, Periplaneta americana. This work constitutes the second total synthesis of periplanone B, and it was reported approximately five years after the landmark periplanone B synthesis by W.C. Still9 (see Chapter 13). As in the first synthesis by Still, Schreiber s approach to periplanone B takes full advantage of the facility with which functionalized 5-cyclodecen-l-one systems can be constructed via anionic oxy-Cope rearrangements of readily available divinylcyclohexanols.5 7 In addition, both syntheses of periplanone B masterfully use the conformational preferences of cyclo-decanoid frameworks to control the stereo- and regiochemical course of reactions carried out on the periphery of such ring systems.10... 

Synthesis (Freed and Potoski (American Home), 1971 Freed, 1973 Kleemann et al., 1999,) Dezocine is prepared through the following sequence The condensation of 1-methyl-7-methoxy-2-tetralone with 1,5-di-bromopentane by means of NaH or potassium tertbutylate affords 1 -(5-bromopentyl)-1 -methyl-7-methoxy-2-tetralone this product is cyclized with NaH to give 5-methyl-3-methoxy-5,6,7,8,9,10,11,12-octahydro-5,11 -methano-benzocyclodecen-13-one i. The ketone i, by reaction with hydroxylamine hydrochloride in pyridine, is converted into its oxime ii, which is reduced with H2 over Raney Ni to a mixture of isomeric amines which were separated by crystallization of the HCI salts giving 5-a-methyl-3-methoxy-5,6,7,8,9,11 a, 12-octahydro-5,11 -methanobenzo-cyclodecen-13p-amine, which is finally cleaved with concentrated HBr. 

A convenient new synthesis of cis- and trans-cyclodecene by Traynham et al.1 utilizes as starting material cyclodecane, now available from Columbian Carbon Co., Lake Charles, La. 70601. Chlorination, with irradiation from a 150-w. light bulb, affords 1 -chlorocyclodecane. One portion of the product was dehydrohalogenated as... 

The full report on the synthesis of the hexano-bridged oxepin (140) has now appeared and further work has been reported on its oxidative cleavage to give cyclodecenes and cyclodecadienes, and on some addition reactions. The structure of the dehydration product of 2,6-di-t-butyl-4-phenyl-l-(p-tolyl)cyclohexa-2,5-diene-l,4-diol, previously postulated as a fully unsaturated oxepin, has now been confirmed by X-ray analysis. ... 

Improved conditions have been found for the synthesis of cycloalkynones by Eschenmoser fragmentation of bicyclic epoxy-ketones. Various cyclodecene derivatives have been prepared from the Diels-Alder adduct of cyclo-octyne and furan-3,4-dicarboxylates, ° and some simple cyclodecanones have been obtained from 9-decalinols by radical-induced ring cleavage. ... 

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