Novel p-lactone

Two recent examples of isolation are gentisyl quinone isovalerate [185] and a novel p-lactone, vittatalactone [(3R,4R)-3-methyl-4-(l,3,5,7-tetramethyloctyl)oxetan-2-one [118]. The fornier is a female sexual pheromone which was isolated from the German cockroach Blattella germanica), and the latter is an aggregation pheromone which was isolated from collections of airborne volatile compounds from feeding male striped cucumber beetles, Acalymma vittatum. 

Subsequently, Romo et al. studied an intramolecular nucleophile (O-acetyl quinidine, O-Ac-QD) catalysed aldol-lactonisation (NCAL) process of achiral acid-aldehydes (R = R ) promoted by a modified Mukaiyama reagent (Scheme 15.10) and EtsN, providing p-oxoketenes in situ, leading to a variety of novel p-lactone-fused bicyclic systems. This process was then extended to keto-acid substrates and more recently to racemic substrates (R t R ) demonstrating the utility of the Cinchona alkaloid catalysts O-TMS quinidine (O-TMS-QD) and O-TMS quinine (O-TMS-Q), in doubly diastereoseleetive NCAL reactions. ... 

An enantioselective total synthesis including an HNL-catalyzed step of the pheromone vittatalactone, a novel P-lactone originally isolated from feeding male striped cucumber beetles, Acalymma vittatum was recently published. PaHNL catalyzes with high enantioselectivity (>96% ee) the formation of the (R)-cyanohydrin from crotonaldehyde 9 a key step in the synthesis of one of the two main building blocks 11 (Scheme 28.5). ... 

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See also in sourсe #XX -- [ , , ]

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