Synthesis of 2-sulphur-substituted 1,4-anthraquinones. Application to the Synthesis of Anthracyclinone Precursors
摘要:
2-sulphur-substituted 1,4-anthraquinones 8a,b and 10 have been prepared by annelation reactions of the anions of furanones 5a,b with naphthoquinone monoketals of type 6 and 9. Diels-Alder reaction of the 1,4-anthraquinones 11a,b with (E)-1,3-bis(trimethylsilyloxy)buta-1,3-diene (12) affords ABCD tetracyclic systems related to those existing in anthracyclinones.