259097-27-3Relevant academic research and scientific papers
Reduction of 1-nitrospiro[2.2]pentanecarboxylates: Convenient synthesis of novel polyspirocyclic cyclopropane amino acids
Yashin, Nikolai V.,Averina, Elena B.,Grishin, Yuri K.,Kuznetsova, Tamara S.,Zefirov, Nikolai S.
, p. 279 - 284 (2006)
A facile method for the preparation of a series of racemic spiropentane amino acids is described. An approach involving sequential catalytic cyclopropanation of polycyclic methylenecyclopropanes with nitrodiazoesters and reduction of the nitro group is described. Georg Thieme Verlag Stuttgart.
Cyclopropyl building blocks for organic synthesis, 53([≠]). Convenient syntheses of novel α- and β-amino acids with spiropentyl groups
De Meijere, Armin,Ernst, Katrin,Zuck, Bernd,Brandl, Melanie,Kozhushkov, Sergei I.,Tamm, Markus,Yufit, Dmitrii S.,Howard, Judith A. K.,Labahn, Thomas
, p. 3105 - 3115 (2007/10/03)
Racemic spiropentylglycine (8) has been synthesized by sodium borohydride reduction of benzyl (E/Z)-2-chloro-2-spiropentylideneacetate (5- Bn), nucleophilic substitution of the chlorine in the product 6 with azide and hydrogenolytic deprotection of the resulting 7 (overall yield 15%). An alternative approach to 8 consisted of the coupling of the higher-order cuprate 10, generated by halogen-metal exchange from bromospiropentane (9), with the electrophilic glycine equivalent 11 followed by deprotection (overall yield 47%). Enantiomerically pure (1'-aminospiropentyl)acetic acid [(R)-16] (overall yield 16% from 5-Me) and 1-aminospiropentanecarboxylic acid [(R)-23] (29% from 5-Me) were obtained from the Michael adduct 14-Me of (4R,5S)4,5-diphenyloxazolidin-2-one (13) and methyl (E/Z)-2-chloro-2- spiropentylideneacetate (5-Me). Racemic 1-aminospiropentanecarboxylic acid (R/S-23) was prepared by rhodium-catalyzed addition of dimethyl diazomalonate to methylenecyclopropane and subsequent Curtius degradation of the half-ester 28 via the azide 29 (overall yield 14%). Upon standing in aqueous solution, 23 underwent complete rearrangement to the new 1-amino-2- methylenecyclobutanecarboxylic acid (24). The interesting derivative of azabicyclo[3.1.0]hexane-1-carboxylate 34 with an annelated spiropentane moiety and a β-amino acid fragment was incidentally obtained in a one-step intermolecular domino reaction starting with the addition of lithium benzylamide to methyl 2-chloro-2-cyclopropyhdeneacetate (32, 41% yield).
