Seebach-alkylation

The synthesis of the C20—C26 fragment started with a 4-alkylation of methyl aceto-acetate The first stereocentre was introduced by enantioselecuve catalytic hydrogenation with Noyort s (S)-binap rhodium complex (cf p 102f.) Stereoselective Frater-Seebach alkylation with allyl bromide introduced the second stereocentre in 90% yield (cf p 27) Stereospecifid introduction of the stereocentres C24 and C2 was achieved by a chelation controlled addition of an allylstannane to an aldehyde (see p 66f) After some experimentation with Lewis acid catalysts and reaction conditions a single diastereomer of the desired configuration was ob-... [Pg.325]

Certain 2,5-dialkyl-pyrrolidines, which are trail pheromones of the pharaoh ant (Monomorium pharaonis L.), have been synthesized by application of the Hofmann-Loffler reaction to 5-aminotridecane and 7-aminopentadecane. The same type of compound results from Seebach alkylation of TV-nitrosopyrrolidines.4... [Pg.35]

Fragmentation reactions, 89-90, 141-142 Frater-Seebach alkylation, 27, 325-326 Friedel-Crafts acylation ... [Pg.210]

Other references related to the Frdter-Seebach alkylation are cited in the literature. ... [Pg.1122]

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