222736-63-2Relevant academic research and scientific papers
C2-symmetric enantiopure ethanotethered bis(α,β-butenolides) as templates for asymmetric synthesis. Application to the synthesis of (+)-grandisol
De March, Pedro,Figueredo, Marta,Font, Josep,Raya, Javier,Alvarez-Larena, Angel,Piniella, Juan F.
, p. 2437 - 2447 (2003)
Starting from D-mannitol, we have prepared several C2-symmetric ethanotethered bis(α,βbutenolides) and studied their [2+2] photocycloaddition reaction with ethylene. The protective groups of the central diol unit have a noticeable influence on the facial selectivity of the cycloaddition, the bis(trimethylsilyloxy) derivatives showing the highest diastereoselectivity. A theoretical conformational analysis of the substrates in the ground state is in good agreement with the diastereofacial selectivity experimentally observed. The bis(photocycloadducts) have been converted into the enantiopure cyclobutanes formally derived from the photoreaction of ethylene with γ-0hydroxymethylα,β-butenolide, in which only a moderate facial selectivity had been previously found. As an application of these studies, we have developed a highly efficient and stereoselective synthesis of (+)-grandisol.
C2-symmetric enantiopure bis-α,β-butenolides as diastereoselective substrates in ethylene photocycloaddition
De March, Pedro,Figueredo, Marta,Font, Josep,Raya, Javier
, p. 2205 - 2208 (1999)
Several C2-symmetric bis-α,β-butenolides have been synthesised starting from D-mannitol. Their [2+2]-photocycloaddition to ethylene has been studied as a model reaction to evaluate the influence of the protecting groups of the central diol system on the facial diastereoselectivity. The trimethylsilyl derivative shows the highest selectivity. The bis-cyclobutane containing products have been converted into the enantiopure adducts of γ- hydroxymethyl-α,β-butenolide and ethylene.
