Description:
It is introduced that an N-MOM-tetrahydrocarbazole-fused tetrahydrofuran is a new intermediate for the synthesis of olivacine. Upon treatment with DDQ in a mixture of H2O-THF at 80 °C, it undergoes ring-opening, MOM-removal and aromatization in one pot to yield 1-methyl-carbazole-2-ethanol, an already known precursor for olivacine. Besides, several common transformations, such as α-alklylation of N-MOM-protected tetrahydrocarbazole-1-one with ethyl bromoacetate and reduction of a lactone to tetrahydrofuran with Red-Al, have been made good use.