Discussion of the stereochemistry of I is not complete without mentioning the arrangement of the substituents about the ethylenic linkage. The trans configuration of sphingosine has been proved2'by application of Bruni's rule. zs By a similar reasoning it appears very likely that the hydrogen at C1 and the methyl group at Cp are trans in I. Tndeed, meso- dihydroguaiaretic acid dimethyl ether3 provided N-formyl-~-3, 4-dimethoxyphenylalanine ...
