Correspond to those of Table 11. GC internal standards: n-alkanes. Isolated by fractional crystallization on a preparative scale; this work. e Column chromatography preceded GC analysis in both series. tuted olefin^,^^^ which is absent in the 2 isomers. Mass spectrometry indicated the correct molecular ion, whereas the elemental analyses were satisfactory (If0. 30%). Finally, cleavage of the (E)-stilbene-acetals with 10% HC1 in MeOH afforded the ...
