Diastereoselective synthesis of benzofuran-3(2H)-one-hydantoin dyads

作者：Talhi Oualid; Fernandes Jose A; Pinto Diana C G A; Almeida Paz Filipe A; Silva Artur S M^*

来源：Tetrahedron, 2013, 69(26): 5413-5420.

DOI：10.1016/j.tet.2013.04.111

• Benzofuran-3(2H)-one
• Hydantoin
• Diastereoselective synthesis
• X-ray crystallography
• 2D NMR

a-convenient diastereoselective rearrangement of the racemic (R/S)-spirolchroman-2,4%26apos;-imidazolidine]-2%26apos;,4,5%26apos;-triones 3a-c into (2%26apos;R,5S)- and (2%26apos;S,5R)-5-(3-oxo-2,3-dihydrobenzofuran-2-yl)imidazolidine-2,4-diones 4a-c under alkali conditions is described. The obtained sigma bridged benzofuran-3(2H)-one-hydantoin dyads 4a-c are subsequently transformed into pi conjugated benzofuran-3(2H)-one-hydantoin dyads 5a-c by a diastereoselective dehydrogenation using I-2 (catalytic)/DMSO system to predominantly yield the (Z)-isomer. The novel single and double bonded benzofuran-3(2H)-one-hydantoin conjugate structures 4a-c and 5a-c were unambiguously elucidated by single-crystal X-ray diffraction and 2D NMR techniques allowing an in-depth stereochemical and mechanistic discussions.

• 出版日期2013-7-1