Transformations of hispanolone. Novel Michael adducts with in planta activity against rice blast
摘要:
Two novel Michael adducts 9 alpha-cyano-15,16-epoxy-7 beta-hydroxylabda-13(16),14-dien-6-one (2) and 9 alpha-cyano-15,16-epoxy-7-hydroxylabda-7,13(16),14-trien-6-one (3) and the reduction product of 2, 9 alpha-cyano-15,16-epoxy-6 beta.7 beta-dihydroxylabda-13(16),14-diene (4), were synthesized from the naturally occurring labdane diterpene hispanolone (1). Compounds 2-4 exhibited in planta activity against the pathogenic rice blast fungus Magnaporthe grisea. (c) 2005 Elsevier Ltd. All rights reserved.