No abstract

No abstract

No abstract

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.

No abstract