2-nonenal reaction steps

Mannich base. This step was followed by reaction of 125 with a second molecule of formaldehyde to give 126, which undergoes internal cyclization under the reaction conditions used. A fluorous derivative of this ring system has also been published <2005ZOR441> reaction of 3-mercapto[l,2,4]triazole 127 with perfluoro 5-aza-4-nonene gave the bis-perfluoropropyl substituted ring-closed compound 128. 

In some few cases, the acid-base bifunctional Mg(Al)0 mixed oxides have been more active and selective than the rehydrated Mg/Al-LDH (Mg/Al-OH) (Table 9.1). This has been observed in the condensation reaction of heptanal and acetaldehyde yielding 2-nonenal[55] and in MPV reductions/1151 In the former reaction, obtention of 2-nonenal requires in the first step the a-hydrogen abstraction from acetaldehyde. Lewis-type basic sites of moderate strength appear more efficient than Brpnsted-... 

Several routes to cycloalkanes have been developed (Fig. 4). Bolton [29] described the synthesis of azabicyclo[4.3, 0]nonen-8-ones using an intramolecular Pauson-Khand cycliza-tion. The relative stereochemistry was controlled in this cyclization step which proceeded in good yield regardless of whether the nitrogen atom bore an allyl (shown) or propargyl (not shown) substituent. The ene reaction was employed in a route to trans-substituted cyclopentane and cyclohexanes [30], Reductive cleavage from the resin with LiBFL, provided the diol or, alternatively, cleavage with Ti(OEt)4 produced the diester. 

These adducts were thought to occur via attack of the first excited singlet state of propanal on the diene. Evidence from subsequent studies point to the fact that it is likely the excited singlet state of the aldehyde that is responsible for the Patemo-Biichi reaction with 1,3-dienes. This comes from a number of sources and includes evidence from a number of studies . The synthesis of ( )-6-nonen-l-ol, a component of the sex pheromone of the Mediterranean fruit fiy, applied this process as the first step. Hydrogenation and metal catalyzed [2 + 2] cycloreversion gave 165, which was then easily converted to the target by reduction (Scheme 37). 

Preparation of the lactone fragment started with a mixture of (2 ,45) and (25,4S)-4-methyl-2-phenylsulfenyl-y-butyrolactone (53) which was alkylated with ( )-l,9-diiodo-l-nonene. The corresponding iodo compound 100 so obtained was then coupled with the alkyne 99 through the efficient palladium catalyzed reaction (Pd(PPh3)4, Cul, Et3N, room temperature) in 86 % yield. Enyne reduction of 101 with Wilkinson s catalyst, then oxidation of the sulfide into sulfoxide and subsequent thermal elimination gave rise to the title compound 90. The synthesis was achieved in 20 steps and in 0.36 % yield. 

As for us and for basic practical reasons we have chosen to study the selective hydrogenation of 2-pentyl-2-nonenal and, in certain cases, compare the selectivity of this reaction with the one of cinnamaldehyde reaction Furthermore we have used as catalysts, systems whose preparation involved steps similar to those involved in the preparation of ZIEGLER type catalysts which, though initially developed for the polymerization of olefins, have been used since for various reactions. In particular in our laboratory, we have used them for the selective hydrocondensation of carbon monoxide, or methanol, into light olefins (19,20)... 

The synthesis is completed by titanium-mediated addition of ( )-l-(trimethylsilyl)-2-nonene to the aldehyde, conversion of the resulting terminal vinyl group to an acid, jS-lac-tonization, debenzylation, and Mitsunobu reaction with (/S)-A -formylleucine, thus producing the target molecule 308. The last step proceeds with inversion of configuration [63]. 

Aza-adamantanes.—1-Aza-adamantanes are easily available in a convenient two-step synthesis from a-pinene (Scheme 83)." The synthesis is dependent on the serendipitous discovery that solvomercuration-demercuration of a-pinene with acetonitrile in the presence of mercuric nitrate followed by in situ boro-hydride reduction led not to the expected allylic amide but instead to azabicy-clo[3,3,l]nonene which is readily converted into aza-adamantane by reaction with formaldehyde. Rearrangement of A-chloro-N-acetyl-l-aminoadamantane... 

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