摘要 |
Reaction of a 5-substituted resorcinol with a ketal of 4-(1-hydroxy-1-methylethyl)-3-cyclohexen-1-one in the presence of a suitable catalyst effects condensation to provide substantially exclusively a cis-1-hydroxy-3-substituted-6-6-dimethyl-6,6a,7,8,10,10a-hexahydro-9H- dibenzo[b,d]pyran-9-one. |