12662
The two epimers of 1 were resolved through an acetonide reaction , and the absolute configurations of two derivatives were deduced by the analysis of their ( 13 ) C NMR differences induced by gamma - gauche or steric effect .
 Chemical: acetonide; Chemical: ( 13 ) C
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: acetonide; Chemical: ( 13 ) C