D ring intermediates for the synthesis of camptothecin and camptothecin analogs

Year	Description
1993	Invention patented by Daniel L. Comins and Matthew F. Baevsky on March 22th, 1993. Abstract: Processes for making compounds of Formulae XIV, XV, and XVII ##STR1## wherein R.sub.6 is lower alkyl, R.sub.7 is lower alkyl, R is lower alkyl, Y is H, F or Cl, R.sub.8 is a compound of Formula ##STR2## wherein n is 1, 2, or 3, R.sub.11 is C.sub.1 -C.sub.4 alkyl and R.sub.12 is the same as R.sub.11, or R.sub.11 and R.sub.12 together form cyclopentane or cyclohexane, and R.sub.13 is: (a) phenyl substituted 1 to 5 times with C.sub.3 -C.sub.7 secondary alkyl or C.sub.4 -C.sub.7 tertiary alkyl, or (b) selected from the group consisting of naphthyl, anthryl, and phenanthryl optionally substituted 1 to 5 times with C.sub.3 -C.sub.7 secondary alkyl or C.sub.4 -C.sub.7 tertiary alkyl groups, R.sub.10 is C.sub.6 -C.sub.10 alkyl, aryl or alkyl aryl, and Y is H, F or Cl, are disclosed. These processes can be used to make optically enhanced and optically pure forms of the compounds, which are useful in the making of camptothecin and analogs thereof.
Source: selected by the editor from original sources.

Invention: D ring intermediates for the synthesis of camptothecin and camptothecin analogs