... Volume 30, Issue 10, 1989, Pages 1197-1200. ... Download full text in PDF. Tetrahedron Letters,Vol.30,No.l0,pp 1197—1200,1989 0040-4039/89 $3.00 + .00 ... were concentrated to give the crude product, which was purified by column chromatography with 10% EtOAc/hexane as ...