1909
Ultrasound promoted one - pot synthesis of 2 - amino - 4 , 8 - dihydropyrano [ 3 , 2 - b ] pyran - 3 - carbonitrile scaffolds in aqueous media : a complementary ' green chemistry ' tool to organic synthesis .
 Chemical: 2 - amino - 4 , 8 - dihydropyrano [ 3 , 2 - b ] pyran - 3 - carbonitrile
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: 2 - amino - 4 , 8 - dihydropyrano [ 3 , 2 - b ] pyran - 3 - carbonitrile