Preparation and phytotoxicity of novel kaurane diterpene amides with potential use as herbicides.

Novel kaurane ditepene monoamides were synthesized in good yields directly from kaurenoic (1) and grandiflorenic (2) acids and unprotected symmetrical diamines, using a modified protocol for monoacylation. Amides from 1 and 2 and monoamines were also obtained and tested against seed germination and growth of radicle and shoot of Lactuca sativa (lettuce), at 10 -3 , 10 -5 , and 10 -7 M. Amides from symmetrical diamines showed significant inhibitory activity at higher concentrations.