Antineoplastic agents. XXVIII. Camptothecin .delta.-lactone

Abstract

acetate 2. The sole product was formulated as 3P,9adihydroxy-5a-lanost-7-ene (4a) on the following basis.Acetylation with pyridine and acetic anhydride under the usual conditions gave a monoacetyl derivative 4b which still contained a hydroxyl function. Very brief treatment with a trace of mineral acid converted the alcohol 4b into dihydroagnosteryl acetate (3b). The nmr spectrum of alcohol 4a showed the presence of a trisubstituted olefin. Further support for the olefin was provided by the mass spectrum, which displayed an m/e 426 fragment (IC1 -18). The foregoing wouldThe subject of the present communication is a novel synthesis of Schiff bases by intercepting in situ deoxygenated nitro derivatives by aldehydes. Thus, in the presence of a group VI11 metal catalyst (e.g., rhodium carbonyl) , the interaction of benzaldehyde and aromatic nitro compounds under a pressure of (1) For part I, see A. F. M. Iqhal, Tetrahedron Lett., 3385 (1971).

Camptothecin

“…The synthesis of the 6-lactone CLXIII has been achieved through the condensation of triethyl 3ethyl-1 (2) -pentene-1,1,3-tricarboxylate with paraformaldehyde (52), and the preparation of the b-lactone CLXIV has also been reported (53) (Scheme XXVI) .…”