809276-98-0Relevant academic research and scientific papers
Synthesis of a novel enantiopure spiro-b-norestradiol analogue by multiple Pd-catalyzed transformations
Tietze, Lutz F.,Matthias Wiegand,Vock, Carsten A.
, p. 4107 - 4112 (2004)
The novel tetracyclic spiro compound 13 was synthesized by the use of two subsequent Pd-catalyzed reactions. Firstly, the ortho-bromobenzyl chloride 1 was coupled with the enantiopure boronic ester 8, obtained from the Hajos-Wiechert ketone in a chemoselective Suzuki-type reaction to give 12 in 77% yield. Unexpectedly, the intramolecular Heck reaction then did not provide the annulated compound 6, but the spirocyclic compound 13, containing a quaternary carbon center, in 73% yield. The Heck reaction was also performed under microwave irradiation conditions, allowing a considerably shorter reaction time. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
