SMILES: C[C@H]1[C@@H]2CCC3=C([C@]2(CCC1=O)C)CC[C@]4([C@H]3CC[C@@H]4[C@H](C)CCC=C(C)C)C
Description: The molecule is a 3-dehydro-4-methylzymosterol in which the methyl substituent at position 4 has alpha configuration. It is an intermediate in the biosynthesis of cholesterol.