.alpha.-Amino aldehyde equivalents as substrates for rabbit muscle aldolase: synthesis of 1,4-dideoxy-D-arabinitol and 2(R),5(R)-bis(hydroxymethyl)-3(R),4(R)-dihydroxypyrrolidine
摘要:
This work examined the application of rabbit muscle aldolase (RAMA) to stereospecific carbon-carbon bond formation in the preparation of carbohydrates containing amino groups. Several alpha-amino aldehyde equivalents were evaluated as substrates for RAMA and for their synthetic utility in transformations following the aldol reaction. This methodology is illustrated by the syntheses of the pyrrolidine alkaloids 1,4-dideoxy-D-arabinitol and 2(R),5(R)-bis(hydroxymethyl)-3(R), 4(R)-dihydroxypyrrolidine. The kinetic resolution of racemic aldehydes by RAMA and mild methods for transforming the amino equivalents into the desired amines are discussed briefly.
Isonitrile alkylations: a rapid route to imidazo[1,5-a]pyridines
作者:Yajun Li、Allen Chao、Fraser F. Fleming
DOI:10.1039/c5cc08724d
日期:——
Metalated isonitriles react with 2-chloropyridine-type electrophiles in an addition–cyclization route to valuable heterocycles.
金属化异腈与2-氯吡啶类亲电试剂发生加成-环化反应,形成有价值的杂环化合物。
Substrate-Directable Heck Reactions with Arenediazonium Salts. The Regio- and Stereoselective Arylation of Allylamine Derivatives and Applications in the Synthesis of Naftifine and Abamines
The palladium-catalyzed, substrate-directable Heck-Matsuda reaction of allylamine derivatives with arenediazonium salts is reported. The reaction proceeds under mild conditions, with excellent regio- and stereochemical control as a function of coordinating groups present in the allylamine substrate. The distance between the olefin moiety and the carbonylic system seems to play a key role regarding the regiocontrol. The method presents itself as robust, as simple to carry out, and with wide synthetic scope concerning the allylic substrates and the type of arenediazonium employed. The synthetic potential of the method is illustrated by the short total syntheses of the bioactive compounds naftifine, abamine, and abamine SG.
Untersuchungen �ber eine Carbonyl-Olefinierung mit ?-metallierten Isocyaniden. Die Synthese von ?-Carotin und anderen Polyenen
作者:Frank Kienzle
DOI:10.1002/hlca.19730560524
日期:1973.7.18
AbstractThe synthesis of various polyene isocyanides, e.g. β‐ionyl isocyanide and all‐trans‐retinyl isocyanide is reported. Their use in carbonyl‐olefination was investigated and compared with the Wittig reaction. β‐Carotene was obtained from all‐traws‐retinal and all‐trans‐retinyl isocyanide in good yield.