The esterifications of 9-（hydroxyimino）-4-methyl-8,9-dihydrofuro[2,3-h]chromen-2-one （4） with acid chlorides afforded normal oxime-esters 3a-e in 35-78% yields in presence of excessive 4-dimethylaminopyridine as the acid scavenger, whereas the reactions gave unexpected 8-substituted products N-（8-chloro-4-methyl-2-oxo-2H-furo-[2,3-h]chromen-9-yl）amides （5a-c） and 4-methyl-2,9-dioxo-8,9-dihydro-2H-furo[2,3-h]chromen-8-ylcarboxyloates （6d-e） by using excessive acid chlorides. The structures of 10 new compounds were determined by 1H NMR, 13C NMR, MS and HRMS, and the possible mechanism for the formation of unexpected products 5a--c and 6d-e was also proposed.
Eight 16,17-pyrazo-annulated steroidal derivatives were synthesized and evaluated in vitro vascular endothelial growth factor （VEGF） inhibitory activity with 2-methoxyestradiol （2-ME） as the reference compound. Most of the compounds showed potent VEGF inhibitory activity with ECs0 values of micromolar or submicromolar range. Among them, the compounds 3 and 8 exhibited similar EC50 values and obviously better TI values compared with 2-ME.
