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During the structure elucidation of 1,3,4,6,6a,7,8,9,10,10a,l l,lla-dodecahydro-2H-benzo[b] quinolizine-6a,8,9-loa-tetrol (l), a selective acylation of the tertiary loa-hydroxyl was observed. This reaction has been examined in more detail on the 6a18-diacetate derivative 4. It has been found that the acylation is solvent dependent. In pyridine, the secondary 9-hydroxyl is acylated with difficulty. In chloroform and tetrahydrofuran, the 10a-ethyl carbonate is obtained. Evidence is given for postulating that the acylation occurs directly by attack on the tertiary loa-hydroxyl with an assist by the secondary cis-9-hydroxyl and by what appears to be a long-range field effect of the ring nitrogen.

Das Dodecahydrobenzo(b)chinolizintetrol (Ia) liefert bei der Behandlung mit Chlorkohlensäureäthylester in Tetrahydrofuran das 10a‐Äthylcarbonat (Ib) in selektiver Reaktion, während bei dem Diol (II) unter gleichen Bedingungen keine Reaktion eintritt.