C2-symmetric enantiopure bis-α,β-butenolides as diastereoselective substrates in ethylene photocycloaddition
作者:Pedro de March、Marta Figueredo、Josep Font、Javier Raya
DOI:10.1016/s0040-4039(99)00172-0
日期:1999.3
Several C-2-symmetric bis-alpha,beta-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 gamma-hydroxymethyl-alpha,beta-butenolide and ethylene. (C) 1999 Elsevier Science Ltd. All rights reserved.
<i>C</i><sub>2</sub>-Symmetric Enantiopure Ethanotethered Bis(α,β-butenolides) as Templates for Asymmetric Synthesis. Application to the Synthesis of (+)-Grandisol<sup>1</sup>
作者:Pedro de March、Marta Figueredo、Josep Font、Javier Raya、Angel Alvarez-Larena、Juan F. Piniella
DOI:10.1021/jo026705w
日期:2003.3.1
Starting from D-mannitol, we have prepared several C(2)-symmetric ethanotethered bis(alpha,beta-butenolides) 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