1.1: bis(cyclohexanyl)borane; diethylzinc; (+)-DAIB / hexane / -20 - 0 °C 1.2: 0 °C 2.1: tetrabutyl ammonium fluoride / tetrahydrofuran / 20 °C View Scheme

1: C35H60O2Si2 With bis(cyclohexanyl)borane; diethylzinc; (+)-DAIB in hexane T=-20 - 0°C; 2: formyl cyclopropane in hexane T=0°C;