40 
30 
4 
20 
10 
; — Hansel 
311 
y> 
zA^“CH-CH"CH^ 
och 3 
I *0 
CH-OCH-cC r3 
R'=R Z =H: R j =OH 
R ] = R 2 --0"CH 2 -0~; R 3 = OH 
4 4 4 R 1 = r2^ H 
a 
Fig. 18 . UY spectra of the yangonin type compounds and their open chain analogs. 
