Yield:-

Steps:

Multi-step reaction with 2 steps
1.1: K₂CO₃ / acetone / 55 °C
2.1: n-BuLi / hexane; tetrahydrofuran / 0.5 h / -65 °C
2.2: hexane; tetrahydrofuran / -65 - 20 °C

References:

H?gberg, Marita;Sahlberg, Christer;Engelhardt, Per;Noréen, Rolf;Kangasmets?, Jussi;Johansson, Nils Gunnar;?berg, Bo;Vrang, Lotta;Zhang, Hong;Sahlberg, Britt-Louise;Unge, Torsten;L?vgren, Seved;Fridborg, Kerstin;B?ckbro, Kristina [Journal of Medicinal Chemistry,1999,vol. 42,# 20,p. 4150 - 4160]