Synthesis of amino acids of cyclopropylglycine series

symm-Tetramethylenecyclooctane: En Route to Polyspirocycles

“…1,3-Dibromo-5,7-bis(bromomethyl)adamantane (7). 18 Bis-(bromomethyl)adamantane 11 (3.5 g, 10 mmol) was added to a solution of AlBr 3 (1.09 g, 4 mmol) in dry Br 2 (11 mL).…”

“…Three-membered rings, exemplified by cyclopropane and oxirane, are ubiquitous structural motifs present in a variety of natural products, biologically active molecules, and also in aesthetically appealing synthetic polycyclic and caged molecular architectures . The interest in strained small polycycles encouraged broad and extensive studies focused on related problems, from existence and synthesis of highly strained compounds and fundamental aspects of bonding to conformational restriction of physiologically active compounds. − Among these particularly intriguing structures are cyclopropanes spiro-linked to a (poly)cyclic core. The compounds 1 – 3 with two spiro­cyclo­propanes can be cited here as examples (Figure ). − The structures possessing a central cyclic core exhaustively substituted by spiro­cyclo­propanes were named rotanes ( 4 and 5 in Figure ). ,− …”

Asymmetric Carbamoyl Anion Additions to Chiral N-Phosphonyl Imines via the GAP Chemistry Process and Stereoselectivity Enrichments

“… 7 The synthesis of unnatural α-amino amides is often carried out via a Strecker-type process. 8 − 11 This process frequently employs the cyanide ion, which requires two additional steps using harsh conditions to achieve the desired amides. Strong acids and heat are usually needed to convert the cyanide group into the carboxylic acid, followed by amide formation.…”

“…Chiral amines are ubiquitous throughout natural products and pharmaceuticals, and their efficient and economical synthesis is still a highly active research area. − The most important subclass of chiral amines are chiral α-amino amides, which form the basic chemical unit of amino acids and peptides . The synthesis of unnatural α-amino amides is often carried out via a Strecker-type process. − This process frequently employs the cyanide ion, which requires two additional steps using harsh conditions to achieve the desired amides. Strong acids and heat are usually needed to convert the cyanide group into the carboxylic acid, followed by amide formation. − Phenylglycine has been shown to racemize under these conditions, and therefore, the synthesis of phenylglycine amides would be better accomplished through other routes.…”