504
CONMUNICATIONS TO THE
7,y'-imino-bis-butyraldehyde (11) + l-hydroxymrthylpyrrolizidiiie.ll llrc now report the double ring-closure of y , y ' imino-bis-butyraldehyde (II), liberated from the tetracthyl diacetal (I), t o the pyrrolizidine ring system and the concordant synthesis of l-hydroxymethylpyrrolizidine, mainly that racemate (C1,s hydrogens trans) consisting of laburnine (IV)lZ (1,9-hydro~ymethyl-(8p)-pyrrolizidine~~~~~ plus frachelanthamidine (V) (1a-hydroxymethyl- (Sa)p y r r ~ l i z i d i n e ) . ' ~ By , ~ ~ the reaction1? of y-aminobutyraldehyde diethyl acetal18 with y-chlorobutyraldehyde diethyl acetalIg a t 100' under nitrogen YHO I
CHtOEt),
)-
,/-CI-i(OEtj\,
