A scalemic synthesis of the scopadulcic acid skeleton. II: Ring-D formation via regiospecific intramolecular aldol and alkylation reactions

Article abstract of DOI:10.1016/0040-4039(96)01948-X

The propensity of abietenones such as 2 to form exclusively the extended enol(ate) into ring-B can be curbed by introducing an alkoxy group at C-7 in the abietane framework. Thus, the 7-trimethylsilyloxy enone-aldehydes 11 and 13 cyclize to form only the