Amphiphilic reactions by means of exceptionally bulky organoaluminum reagents. Rational approach for obtaining unusual equatorial, anti-Cram, and 1,4 selectivity in carbonyl alkylation
The titanium tetrachloride-mediated alkynylation and allylation of a steroidal aldehyde via stannylacetylenes and allylstannanes with high cram selectivity
The reaction of a steroidalaldehyde (1) with stannylacetylenes (2c) in the presence of TiCl4 produces the Cram isomer (3) with high diastereoselectivity.